The backbeat is the real heart of rock drumming. The basic backbeat boils down to bass drum hits on 1 and 3, and snare drum hits on beats 2 and 4. A stream of 8th notes (constant or syncopated) are played by the right hand on the high-hat or ride cymbal. There are a number of things to think about when sitting down to craft a groove. The first being what the bass player is doing. You see, the bass guitar and bass drum are one instrument played by two people. You want to try and match or hint at the rhythms the bassist is playing with your bass drum. Maybe your playing a rock tune and the bassist is playing a full bar of eighth notes, a real charging kind of feel. You might want play a backbeat with bass drum notes on every eighth note except beats 2 and 4, which is where your snare drum should be.
Checking out some basic drum grooves and seeing them written out can help illuminate the basic patterns of the instrument. Drum notation is quite easy to read actually. Your bass drum is the first F above middle C, snare drum is C an octave above middle C and your cymbal line generally sits at the F, top stave.
I find that many times musicians know more than they think they do about playing the drum set. When you hear a tune, quiet your mind and hear the drums in your head. Sing them! We’ve all got a little drummer man in our heads, you just have to listen to him!