I found my last apt. through
www.rent.net - check them out. This was a couple of years ago though.
Definitely go through the neighborhood at different times of the day and night to gauge traffic, neighborhood safety, and ambient noise (is it across the street from a nightclub, etc...)
If you're looking at a big apartment complex, ask if they have a vacant apartment (other than a model - say, one that's between tenants) that you can see - even if it's not the same size as the one you're looking to rent. This will give you an idea of the level of repair that apts. are kept in, and how extensively they prepare an apt. for a new tenant.