Help! Beginner Trying Test Driven Development.

I'm new to unit testing and Rails in general. I've decided to build my projects in a TDD manner, but this has left me with some early questions. I have this test written out:

describe User do   it "should add user to team" do     team = Team.create(:name => "Tigers")     akash = User.create(:name => "Akash")     akash.teams << team     akash.memberships.size.should == 1     john = User.create(:name => "John")     john.buddyup_with(akash)     john.memberships.size.should == 1     akash.buddys.should include(john)   end end

Ideally, users may join many teams, and teams may have many members. If a user is paired up with another user through "buddyup", those users will share all of the same teams. I've started on the User model, but I'm lost at this point. Can somebody help me out? Here's what I have so far:

class User < ActiveRecord::Base   has_and_belongs_to_many :teams   validates_presence_of :name end

class Team < ActiveRecord::Base   has_and_belongs_to_many :teams   validates_presence_of :name end

All I want to do is pass the test, further functionality will be added later.

class Team < ActiveRecord::Base   has_and_belongs_to_many :teams   validates_presence_of :name end

I suppose you mean :users instead of :teams