Wire brush any rust and other rubbish off the calipers and hubs.
Clean the calipers and hubs thoroughly (i used spray/aerosol brake cleaner - dries instantly so you can start painting straight away)
Have a couple of brushes of different sizes so you can spread it nice and evenly using a larger brush onto the open parts of the caliper, and use a small one to get into all the nooks and crannies.
Dont paint your brake pad clip thing in place.
Dont paint the back of your brake pad.
Spread the paint about - thin coats rather than thick - too much paint and it dries a bit "toffee apple"
Lastly - take your time!