You know how when you ollie, you slide the side of your front foot up the board? Well for a nollie, you do something like that, but it's a little different. You DO slide your back foot, but only a very little. In fact, if you just suck your knees up to your chest, this might all figure itself out for you without you having to concentrate too much on it. That's how it works for some people, but not everyone! So just keep in mind, you slide that back foot up just a bit, until the foot is right over the back bolts.
If you did it right, and if you pulled your knees up to your chest, the board should level out underneath you. Use your feet to level it.
Once that board is level, slam it down to the ground, bend your knees to absorb the shock, and ride away!

