Get into your lane early... When dealing with roundabouts the MSM (Mirror Signal Manouvre) routine is the safest and easiest way to carry out the procedure,the manouvre part is further broken down into position, speed and look.
On approach to the roundabout, look at the road signs, decide where you want to go, and get into your correct lane early, or as soon as it is safe to do so. Follow your lane on the roundabout carefully, by looking at the road markings, also keep an eye on the traffic lights.
Below is a picture of the new multilane whitletts roundabout in Ayr which is controlled by traffic lights 24/7.
Click here or the image below for a bigger picture of the roundabout... and print off a copy to help you if you want.
A lot of people (even experienced drivers) feel nervous about dealing with this roundabout because of all the lanes and traffic lights. All you need to do is take your time on approach, plan where your going early, and get into position in good time, once you're in your correct lane, stay in it as you go, keep an eye on the lights, and watch out for other people crossing lanes in front of you, you should find you'll then come off in you're intended route without much problem.