diff --git a/README.md b/README.md
index 7416d3bd..56dceae0 100644
--- a/README.md
+++ b/README.md
@@ -25,8 +25,9 @@ Operations with complicated contracts (e.g. buying shares) are provided in a sep
 - `functions/`: Firebase cloud functions, for secure work (e.g. balances, Stripe payments, emails). Also contains in
   `functions/src/scripts/` some Typescript scripts that do ad hoc CLI interaction with Firebase.
 
-- `common/`: Typescript library code shared between `web/` & `functions/`. Also contains in `common/envs` configuration for
-  the different environments (i.e. prod, dev, Manifold for Teams instances.)
+- `common/`: Typescript library code shared between `web/` & `functions/`. If you want to look at how the market math
+  works, most of that's in here (it gets called from the `placeBet` and `sellBet` endpoints in `functions/`.) Also
+  contains in `common/envs` configuration for the different environments (i.e. prod, dev, Manifold for Teams instances.)
 
 - `og-image/`: The OpenGraph image generator; creates the preview images shown on Twitter/social media.
 
@@ -34,7 +35,9 @@ Also: Our docs are currently in [a separate repo](https://github.com/manifoldmar
 
 ## Contributing
 
-Since we are just now open-sourcing things, we will see how things go. Feel free to open issues, submit PRs, and chat about the process on Discord. We would prefer [small PRs][small-prs] that we can effectively evaluate and review -- maybe check in with us first if you are thinking to work on a big change.
+Since we are just now open-sourcing things, we will see how things go. Feel free to open issues, submit PRs, and chat about the process on [Discord][discord]. We would prefer [small PRs][small-prs] that we can effectively evaluate and review -- maybe check in with us first if you are thinking to work on a big change.
+
+If you need additional access to any infrastructure in order to work on something (e.g. Vercel, Firebase) let us know about that on Discord as well.
 
 [vercel]: https://vercel.com/
 [jamstack]: https://jamstack.org/
@@ -45,3 +48,4 @@ Since we are just now open-sourcing things, we will see how things go. Feel free
 [cloud-firestore]: https://firebase.google.com/docs/firestore
 [cloud-functions]: https://firebase.google.com/docs/functions
 [small-prs]: https://google.github.io/eng-practices/review/developer/small-cls.html
+[discord]: https://discord.gg/eHQBNBqXuh
diff --git a/web/README.md b/web/README.md
index 8b3e65db..2bfd5056 100644
--- a/web/README.md
+++ b/web/README.md
@@ -2,13 +2,15 @@
 
 ## Getting started
 
-To run the development server, install [Yarn][yarn], and then in this directory:
+To run the development server, install [Yarn 1.x][yarn], and then in this directory:
 
 1. `yarn` to install all dependencies
 2. `yarn dev:dev` starts a development web server, pointing at the development database
 3. Your site will be available on http://localhost:3000
 
-Check package.json for other command-line tasks. (e.g. `yarn dev` will point the development server at the prod database. `yarn emulate` will run against a local emulated database, if you are serving it via `yarn serve` from the [`functions/` package][functions-readme].)
+Check package.json for other command-line tasks. (e.g. `yarn dev` will point the development server at the prod
+database. `yarn emulate` will run against a local emulated database, if you are serving it via `yarn serve` from the
+[`functions/` package][functions-readme].)
 
 ## Tech stack
 
@@ -24,16 +26,17 @@ branch (to production) and PR branches (to ephemeral staging servers that can be
 
 Parts of the file structure that directly map to HTTP endpoints are organized specially per Next.js's prescriptions:
 
-### /public
+### public/
 
 These are static files that will be [served by Next verbatim][next-static-files].
 
-### /pages
+### pages/
 
 These are components that [Next's router][next-pages] is aware of and interprets as page roots per their filename,
-e.g. the React component in pages/portfolio.tsx is rendered on the user portfolio page at /portfolio.
+e.g. the React component in pages/portfolio.tsx is rendered on the user portfolio page at /portfolio. You should
+look in here or in `components/` to find any specific piece of UI you are interested in working on.
 
-### /pages/api
+### pages/api/
 
 Modules under this route are specially interpreted by Next/Vercel as [functions that will be hosted by
 Vercel][vercel-functions]. This is where the public Manifold HTTP API lives.
@@ -52,7 +55,7 @@ integration][prettier-integrations] to format it in your editor.
 [nextjs]: https://nextjs.org
 [vercel]: https://vercel.com
 [tailwind]: https://tailwindcss.com
-[yarn]: https://yarnpkg.com
+[yarn]: https://classic.yarnpkg.com/lang/en/docs/install/
 [prettier]: https://prettier.io
 [prettier-integrations]: https://prettier.io/docs/en/editors.html
 [next-static-files]: https://nextjs.org/docs/basic-features/static-file-serving