1. Write your .thrift file. You may want to use generic.thrift in the examples directory as a starting point. Limited documentation about valid types is available at http://wiki.apache.org/thrift/ThriftTypes. Better documentation is available at http://diwakergupta.github.com/thrift-missing-guide/.
2. Use thrift --gen rb to generate the Ruby bindings.
3. Copy the bindings from the new gen-rb to ruby_thrift_service/lib
4. By default, the server will use whatever version of Thrift that Rubygems provides. If you want to use a specific or vendored version, copy the thrift gem into vendor/thrift[version] and change the requires in server.rb and client.rb to use this version.
5. Implement each method of your server in the ServiceHandler in server.rb. If you want to test your service using a simple Ruby client, implement the client in client.rb.
6. Start the server with ruby server.rb. To test the server, you can connect with the client by using ruby client.rb

This skeleton is based on a blog post by Ilya Grigorik at http://www.igvita.com/2007/11/30/ruby-web-services-with-facebooks-thrift/