From Rap Dictionary
head or heads, pl. (real headz put a z at the end)
- A person, or people: real heads; headz ain't ready; mad headz: Mad Hip-Hop headz use the MPC-2000; Real headz think the Black Eyed Peas are a bunch of sell-outs.
- Getting head: getting a blow job. All the fellas in the house say this, "This head is so damn good" -- Luke with Notorious B.I.G. (Bust A Nut) 
- The burning top of a joint or sigarette.
- In the Army, the "head" is the toilet.
- the Foam on top of beer in your mug.