Add instructions to CONTRIBUTING.md

CONTRIBUTING.md

@@ -1,16 +1,39 @@
 # How to contribute
 
-We definitely welcome patches and contribution to grpc! Here is some guideline
+We definitely welcome patches and contribution to grpc! Here are some guidelines
 and information about how to do so.
 
-## Getting started
+## Sending patches
 
-### Legal requirements
+### Getting started
+
+1. Check out the code:
+
+        $ go get google.golang.org/grpc
+        $ cd $GOPATH/src/google.golang.org/grpc
+
+1. Create a fork of the grpc-go repository.
+1. Add your fork as a remote:
+
+        $ git remote add fork git@github.com:$YOURGITHUBUSERNAME/grpc-go.git
+
+1. Make changes, commit them.
+1. Run the test suite:
+
+        $ make test
+
+1. Push your changes to your fork:
+
+        $ git push fork ...
+
+1. Open a pull request.
+
+## Legal requirements
 
 In order to protect both you and ourselves, you will need to sign the
 [Contributor License Agreement](https://cla.developers.google.com/clas).
 
-### Filing Issues
+## Filing Issues
 When filing an issue, make sure to answer these five questions:
 
 1. What version of Go are you using (`go version`)?