This might help too:
http://www.urban75.org/brixton/bars/index.html
Probably the pick of the bunch are:
Prince Albert, but it's the opposite way to the Academy when you come out of the tube, turn left, then turn left again at the KFC and it's halfway down Coldharbour Lane. Good, lively, punk rock Brixton boozer.
The Trinity - Quiet pub on a little square just off Acre Lane
Canterbury Arms - Irish pub five mins from the Academy, the traditional pre-Academy boozer.
Effra Tavern - lovely old school Brixton pub, you'll get a proper mixture in here. But it's left out of the tube, and about a five-ten mins walk.
If you just want a pint and don't care where you are, then:
The Beehive, on the way to the Academy. All human life is in here!
Ivan's Retreat, opposite the Beehive. Like a pub you'd get at an airport.
I live in Brixton so fire away if you have any questions.