Remember this rule of thumb: always occupy your legal spot. Vehicles exiting from the roundabout have the right of way, so not much of a problem unless you're on the wrong side. Position your vehicle towards your point of exit: left if you're going to the left or taking a u-turn, right if you're going to the right, and center if you're going straight.

Now for small round-abouts- like the one at The Center- your signal light spells a big difference. Just signal your intention so that other vehicles can give way to you.

Hope this was of help. Drive safe! :)