that would depend on the function(s) you are attempting to use, unless you would like include them all?

Its easier to answer that question after knowing what you are trying to do specifically, or what function(s) youre after.

Well, for starters, I'd like to work with some user functions. b2 must have some "make sure the current user is who he says he is" feature, with some way to return the currently logged in user. What do I include, and how do I access the current user's username?

Also, I've created another few columns in the evo_users table to control access to specific static pages. How can I use b2's connection to the db to query the evo_users table? Am I better off just making my own connection and using that?