If you're a beginner, you want to get this move down before you start on anything else. Toprock is not technically difficult to do and allows you to express your own style.
Toprock is the thang peeps do when their on their feet, before molesting the floor. Some peeps refer to it as shufling-its not really. The point of it is to form the circle, get people's attention, and get some room to bust yer moves. There's all kinds of variations on this, but there is a proper way. You dont really need to know how to do this, but it helps to be able to go from Toprock to 6-step or flares. The main thing is that it looks good, keep with the hip-hop style, and relax.
The proper Toprock is a 4 step, 4 beat dance that's pretty simple to learn.
Start with your feet together standing up.
1) Hop forward onto your right toe.
2) Skip back onto your left foot, you can add a lil hop/kick back.
3) Now your right foot goes behind you and to the left, your body can turn with it.
4) Your left foot skips back again and you're in the starting position.
Try it out and make it look good. Add your own style and attitude. To go from this to flare, take a slightly wider step back with your left foot on either step 2 or 4. To go into 6-step, just go into step 3 (of the 6-step) wherever it feels comfortable, probably after step 4.