OpenStreetMap Database Schema - Postgis

Dear All,

I am looking for documentation on the OSM schema for Postgis, although there are very few tables, I want to know the possible values that can be found in each of the columns and something describing what type of data can be found where. Thanks.

Best Regards,
Faheem Merchant

Also a follow up to this question, in the planet_osm_polygon table what are the units for the way_area. For example, buildings in a city have a way_area but am not sure what is the footprint area measured in, is way_area square meters, square feet, etc.?