README.md in postit-0.1.1 vs README.md in postit-0.1.2

@@ -1,2 +1,43 @@
 # PostIt
 ## The Bundler Version Manager
+
+```bash
+$ gem install postit
+```
+
+Bundler is great at managing your gem dependencies, but if you've ever thought
+"What I really need is a way to manage my _bundler_ version" -- look no further!
+
+PostIt has a few different modes of operation, all of which attempt to make
+keeping your team on a consistent bundler version a breeze.
+
+### Usage
+
+The main way of using PostIt is via the `postit` command -- you can use it just
+like the `bundle` command, and PostIt will handle invoking the correct bundler
+executable and forwarding along all of your arguments. So to `bundle install`,
+you'd just run `postit install`, etc.
+
+Additionally, if you have `require 'bundler/setup'` anywhere in your code, you
+can replace it with `require 'postit/setup'` and it will activate the correct Bundler version and then `require 'bundler/setup'`.
+
+If you're building tooling and want to know what version of Bundler PostIt has
+inferred, you can run `postit --bundler-version` to have that version printed to
+`STDOUT`.
+
+### Bundler Version Selection
+
+#### `Gemfile.lock`
+
+By default, PostIt will read your Bundler version from your `Gemfile.lock`,
+meaning you don't have to do anything special to use the same bundler version as
+the rest of your team -- just `postit install` and PostIt will automatically
+infer the correct Bundler version for you.
+
+#### Command Line Argument
+
+When invoking `postit`, you can specify the Bundler version as the first argument, so to run `bundle exec` with Bundler 1.9.6, for example, you can do `postit 1.9.6 exec`.
+
+#### Environment Variable
+
+Setting the `BUNDLER_VERSION` environment variable to the desired Bundler version will work as if you'd passed the version as a command line argument.