I did my brakes not long ago. Used loads of brake cleaner and popped one of the piston's out by accident. Managed to get it back in and then filled up the brake resorvior.
Thought I had knackered it coz it took fooking ages to get the brake lever to feel hard. Was a case of keep bleeding till it works. You will think it's taking too long then your brake will go solid. First time I used the brake I locked the front up.
Make sure you keep the resorvior topped up coz if you don't you'll send air in the top and have to start again. I did mine and haven't done brakes before so it's not that hard, just time consuming as Xphyral says.
Another good idea is a ring spanner. Saves pissing about and any chance of the spanner slipping off while the nipple is open. I also found it easier to get someone to help pulling the brake lever as I got short arms.
