RoR application design for real estate web site

I'm trying to implement a real estate app. But i'm stuck at designing
models associations. I's my first RoR app.

Situation

The app has different types of properties/estate(house, apartment,
garage, land etc). These properties have some common attributes(name,
price, description) and some specific ones for different types of
property. But those specific ones can be common for some types.

Problem

I need to implement CRUD actions on these. And some search form with
filters. Basically, all standard stuff for a Real Estate web site.

p.s. Sorry for my english. I hope you'll understand what i meant:)

You can see some projects at http://www.opensourcerails.com/ with source codes included. My sugestion to you: learn from GitHub, partipate, commit to that projects.

as suggested by Daniel, search Open Source Rails, and you will find what you are looking for.