README.md in drg-0.3.0 vs README.md in drg-0.4.0

@@ -20,19 +20,67 @@
 
 ## Usage
 
 ### Pinning Gems
 
-DRG can help you manage your project's gems by updating your Gemfile with pinned versions. Just run:
+DRG really wants to help you manage your project's gems. But DRG doesn't want to replace Bundler. Instead we want to build on
+it. You can "pin" all your versions to the current version listed in the Gemfile.lock:
 
 ```bash
 rake drg:pin
 ```
 
+Which will change gems list in your Gemfile to their full version. So if you have a gemfile that looks like:
+
+```ruby
+gem 'rails'
+gem 'byebug', require: false
+gem 'therubyracer', '~> 0.12', platforms: :ruby
+
+# gotta include ourselves
+gem 'drg'
+```
+
+to
+
+```ruby
+gem 'rails', '4.2.3'
+gem 'byebug', '5.0.0', require: false
+gem 'therubyracer', '0.12.2', platforms: :ruby
+
+# gotta include ourselves
+gem 'drg', '0.3.1'
+```
+
+Although, you may want to pin gems with their _minor_ version (which allows updating patches). To do this, just run:
+
+```bash
+rake drg:pin:minor
+```
+
+This will change a gem listed like
+
+```ruby
+gem 'rails', '4.2.3'
+```
+
+to 
+
+```ruby
+gem 'rails', '~> 4.2'
+```
+
+Pinning ignores gems that are fetched from somewhere other than rubygems. For example, gems listed with `:git`, `:github`, 
+or `:path` will be ignored.
+
+There is also a `rake drg:pin:major` that does what you think.
+
+This can be combined with `bundle update` to quickly update all gems to the latest patch level.
+
 ### Updating Gems
 
 DRG can also try to update all outdated gems to the most recent version. It'll update the gem and run your tests. If your
-tests pass, then it'll update your gemfile with the current version. Similar to what Gemnasium offers.
+tests pass, then it'll update your gemfile with the current version. Similar to what Gemnasium offers (experience may vary).
 
 ```bash
 rake drg:update
 ```