Beginning writing RSpec with Rails model plugin

I want to write a Rails model plugin using RSpec. I’m using Rails 3,
Ruby 1.9 and RSpec 2.

I’ve read the RSpec and Rails documentation but haven’t found any
examples of using RSpec in a Rails 3 plugin situation.

Is there a plugin someone can recommend that I can study that would help
me set up the environment and set me on the task of writing code?

Sincerely,
Jose