[Gayle]

This is from the Highway Code and has a little picture to explain roughly what I said.

When reaching the roundabout you should

give priority to traffic approaching from your right, unless directed otherwise by signs, road markings or traffic lights
check whether road markings allow you to enter the roundabout without giving way. If so, proceed, but still look to the right before joining
watch out for all other road users already on the roundabout; be aware they may not be signalling correctly or at all
look forward before moving off to make sure traffic in front has moved off

186
Signals and position.

When taking the first exit to the left, unless signs or markings indicate otherwise
signal left and approach in the left-hand lane
keep to the left on the roundabout and continue signalling left to leave

When taking an exit to the right or going full circle, unless signs or markings indicate otherwise
signal right and approach in the right-hand lane
keep to the right on the roundabout until you need to change lanes to exit the roundabout
signal left after you have passed the exit before the one you want

When taking any intermediate exit, unless signs or markings indicate otherwise
select the appropriate lane on approach to the roundabout
you should not normally need to signal on approach
stay in this lane until you need to alter course to exit the roundabout
signal left after you have passed the exit before the one you want
When there are more than three lanes at the entrance to a roundabout, use the most appropriate lane on approach and through it.