use the rated_by_user method
@rate.rated_by_user?(@session[:user]) and user?
rateable_id is the id of the table you are rating
so for you, rateable_id will be equal to address_id
user_id should be the id of the user who posts the rate, this is used to ensure that a user only rates something once.
there is an example of my rating system at www.blogsaic.com
it works pretty much like the rating system at youtube
login and rate some tiles
if you want a similar system, I can give you all the bits of code you need