You should probably set up your app with a navigation controller and a tableview(the xCode navigation app template is a good starting point, as it sets your rootview controller up as a tableview and also gives you the navigation controller already setup) Then use the tableviews didselectrowatindex method to push a view controller with your definition.
You should also look at subclassing UIViewcontroller for the definition viewcontroller.
Tab bars and Navigation bars together - O'Reilly Broadcast
Isn't a bad place to start; although the tutorials are for a nav controller within tabbar, the functionality of the nav controller and the tableview are what you want. Do be careful however as the tutorial subclasses the tableview as well (which caused be problems until I realised it and removed it (thanks to Brianslick btw))
Hope this helps.
