Roundabouts are there to keep traffic flowing if it is safe, the whole idea is to maintain progress but give way to the right or any vehicle already on the roundabout. They can cause confusion and fear, particularly among inexperienced learner drivers, but once you understand the rules and get plenty of practice you will soon feel confident and capable dealing with roundabouts.
The most important thing to remember approaching a roundabout is to gradually slow down, this will give you time to preview the roundabout and hence your decision will be easier to make if you are more informed. You must stop and let any vehicles go if they are already on the roundabout or approaching from the right. However if they are a long way from you then you should be able to proceed if there is a big enough gap.
Stay left if going left, using the left lane making sure to indicate left well in advance of the roundabout and leaving the indicator on until you are safely off the roundabout. If going straight, stay left as well only indicating left once you pass the first exit. And if taking the third exit to the right stay right and use the inside lane, indicating right as you approach and then indicating left after you pass the second exit. This is generally the way it works on roundabouts unless signs or markings say otherwise.
Remembering the word SPOT can help as each letter is an important aspect in relation to dealing with the roundabout. S is to slow down, P is position, O is observation and T is timing of the signals. So if you slow down in good time, have a clear understanding of which lane you should be in, give plenty of quick looks to the right and use your signals properly and in good time then you should be fine.
Practice different types of roundabouts, from standard to mini, from large to small, to help you build your confidence.