26 resources from Y Combinator Startup Library we point founders to, and the questions each answers.
▶️ Video
✓ Link checkedFreeBeginner
Why we picked it
Michael Seibel's crisp framing of holding the problem and customer tightly while holding the solution loosely, the mindset that keeps competitor and problem research honest. Free and canonical.
Why we picked it
The canonical, no-nonsense overview of how seed fundraising works, written by a former YC president who has seen thousands of rounds. It's the single best starting point before you talk to a single investor.
Why we picked it
A concise video lecture that walks through the key concepts and mechanics of running a fundraising process, from a YC partner who has coached thousands of founders. Great if you'd rather watch than read.
Why we picked it
YC's fundraising library collects the canonical explainers on how SAFEs convert, how caps and discounts work, and how they dilute you. The most trustworthy free explanation of the instrument almost every seed round uses.
Why we picked it
Michael Seibel, who ran YC, makes the blunt case for shipping something almost embarrassingly simple and learning from real users instead of chasing a perfect first version. His line that if it takes more than a month to build, it is not an MVP is a practical yardstick for anyone stuck polishing. Watch it when the urge to add one more thing before launch takes over.
Why we picked it
This is the plainest, most credible list of the traps that keep founders from their first customers, written by the people who have watched thousands of startups try. It names the exact failure modes you are asking about: not knowing where your first users will come from, not talking to users, and prioritizing press and hiring over getting the product in front of real people. Treat it as a checklist of what to not do, not a formula for success.
Why we picked it
This is the canonical structure for the investor cold email, written by a YC partner who reads them from the other side. It is short and prescriptive: what to say, in what order, and why brevity beats a long pitch. Treat it as the skeleton you fill in, not a script to copy word for word.
Why we picked it
This is the exact list a founder gets handed once a term sheet lands, written by YC Continuity's general counsel after hundreds of financings, so it is the request list itself and not a vendor's marketing checklist. It spells out the corporate, equity, IP, and financial documents investors ask for, and it makes the core point plainly: assemble the data room before you sign, and you cut about a week off closing. Treat it as a starting point to pre-build your folders, not a legal opinion on your specific deal.
The scramble is avoidable: having board minutes, stockholder and option lists, incorporation docs, and recent financials ready before the term sheet saves roughly a week at closing.
Investors want the paper trail of your equity (who owns what, at what price, on what dates), so a clean cap table and signed option agreements sit at the centre of the ask.
This is post-term-sheet reality, so build the folder structure now while things are calm rather than reconstructing it under a deadline.
Why we picked it
This is the canonical founder-side explainer of what a board actually is and when you owe someone a seat. It spells out the standard seed board (two founder seats, one investor seat, so founders keep the majority), why an outside/independent director gets added, and what the board formally approves, which is the exact gap between a board member and someone who just gives advice.
At seed the board is usually two founder seats plus one investor seat, so founders keep voting control; you do not have to give a seat at all if the round does not require it.
A board director votes on and approves the decisions that matter most (budgets, hiring or firing the CEO, selling the company, the next raise), which is a different thing from an advisor.
The independent seat is the swing vote; treat who fills it as a real decision, not a formality to hand the investor.
Why we picked it
A short, no-nonsense walkthrough of which handful of numbers actually matter at your stage, straight from YC's own coaching material. It's the right first stop if you've never set up a metrics dashboard and don't know where to start.
Why we picked it
Blomfield (founder of Monzo and GoCarchless, now a YC partner) gives the concrete mechanics of closing that first B2B deal: pick one wedge product and sell it hard for a couple of weeks, run paid pilots not vague free design partnerships, and use opt-out contracts to convert. It is the tactical how-to for turning your one target customer into a signed, paying pilot while you are still employed.
Charge for the pilot: a paid pilot with clear success criteria is real proof; a long, undefined free design partnership is the most common founder mistake and proves nothing
Pick a narrow wedge and sell it aggressively for two weeks; if it does not land, switch the wedge rather than piling on features
Find and cultivate an internal champion who sells for you when you are not in the room, which is how a single evening-and-weekend deal actually closes inside a company
Why we picked it
This is the piece that pushes you to write down your success number before you launch, exactly the discipline our answer asks for. It's a quick read on how to pick one goal that's specific enough to actually fail at.
Why we picked it
Segment's founder walks through failures and near-misses so you can feel the contrast between not having fit and having it. Because it shows the wrong turns as vividly as the right one, you learn to spot the difference in your own product. A grounded case study to sit alongside the frameworks.
Why we picked it
Once you have a list of people to reach cold, this shows you how to write emails they actually answer. Seven concrete principles (short, human, personalized, credible, clear ask) with examples. It pairs directly with the go to them, do not wait for them idea.
Why we picked it
Tom Blomfield's practical framework for pricing when you sell to businesses, including why to charge from the start and how to talk about money without flinching. Direct and tactical for founders selling to companies rather than consumers. It pairs well with the Kevin Hale talk.
Why we picked it
A compact YC piece that reframes the MVP as a minimum evolvable product, something you keep changing in response to your earliest users. It ties getting first users directly to listening and iterating, not just launching. Good short read to align your team on why the first users matter beyond the vanity of signups.
Why we picked it
Taggar covers the full arc: why a co-founder matters, when to bring one on, where to look, and how to keep the relationship healthy once you have one. It is the best single overview if you are still deciding whether to search at all. It pairs well with actually running a small project together before you commit.
Why we picked it
A useful reality check on meeting a co-founder cold rather than through years of shared history. It sets expectations for how long the process really takes and what a good match actually looks like. Read it so you neither romanticize nor dismiss the matching route.
Why we picked it
Finding a great engineer is only half the battle when everyone is competing for them, and this piece is about the other half: getting the offer accepted. It covers how to present an offer, close on mission and problem, and raise your acceptance rate. Useful precisely because in a talent war your close rate matters as much as your pipeline.
Why we picked it
A Startup School talk with a YC partner and Triplebyte's co-founder on finding and hiring key engineers from scratch. Triplebyte's whole business was engineer assessment, so the sourcing and evaluation advice here is grounded in a lot of real hiring data. Watch it for a structured view of building the team beyond a single hire.
Why we picked it
Y Combinator's own primer on the legal machinery of a startup, including why everyone must assign IP to the company or there is nothing of value to fund. It is short, opinionated, and reflects what YC actually requires of its founders. Read it to understand the standard investors will hold you to.
Why we picked it
Before you can run short cycles you have to decide what goes in them, and this is a founder grade framework for that from the person who built Justin.tv and Twitch. Shear is concrete about tying each candidate feature to one or two metrics that matter. Watch it to keep your bets small and pointed instead of trying to do everything.
Why we picked it
Kevin Hale distills a pitch into seven questions investors need answered, and 'why this team' is one of them. Use it to place your 'why you' story inside a clear, concise pitch instead of leaving it to chance. It shows how founders often bury their strongest personal signal.
Why we picked it
Written for the founder who built the product and is now terrified of the word sales, this argues the skill set is closer to debugging than performing: listen carefully, form a hypothesis about the buyer's problem, test it, iterate. It is a good mindset reset if you keep avoiding outbound because you assume you are bad at it. Read it before your next customer call, not after you have already talked yourself out of making one.
Why we picked it
Meesho's co-founder describes how the company's first idea (a hyperlocal shop-discovery app) failed and how the real business came from noticing women already reselling on WhatsApp in small towns. It's a direct, first-person account of pivoting on what customers were already doing rather than what the founders had planned to build.
Why we picked it
Chesky describes flying across the country to personally sit in hosts' living rooms because nothing in a survey told them why hosts hesitated to list their homes. It is the clearest founder-told example of show, don't ask, applied to a product nobody had seen before.
