I'm going through a newly created site and am trying to deactivate all the modules that I won't need. I'm familiar enough with some of them to know what effect turning them off will have, but with others I end up having to poke around the module's code for a while to get a feel for what it does.

Is there any existing documentation for the core modules that gives a general overview of what each module does? (Eg. Mage_Wishlist: Allows logged in users to save a list of items with their account that can be added to the cart at a later time.)