Just have a look at this, them never go to Swindon, but aside from that all the above points are spot-on, no cra in London use one everywhere else.
http://www.swindonweb.com/life/lifemagi0.htm
Merrin
merrin that’s very similar to the one on Hemel I mentioned 
since roundabouts seem to be the main problem i will give an easy lesson.
for left (1st exit) stay in left lane, indicate left, drive off when no-one is coming at you.
for straight across (2nd exit), stay in left lane, don’t indicate until you’ve passed the first exit, then drive across.
for right (3rd exit) stay in right lane, indicate right, then when you are past 2nd exit indicate left and carefully change lane to turn off.
be aware that not all drivers will follow these rules. many people going straight over the intersection do so in the right lane because it’s faster. be wary of them.
if roundabout has more exits than this, do whatever seems most logical, most of the other drivers will be working on the same principle.
good luck!
it is acceptable to wait longer at intersections in the uk than the us. use higher driver patience to your advantage.
Noone seems to have said it - unless I missed it - but at roundabouts you give way to the right. So, if traffic is waiting to come on from a junction on your immediate right, you wait. Similarly, if traffic is on the rbt (ie. coming from your right) you wait.
Just in case…!!
Have a good trip!
I’ve swapped back and forth between left- and right-hand driving over the years. Occasionally I’ve set off on the wrong side of the road. A few years ago, some American friends of mine set off on the wrong side of the road in Ireland and had a head-on collision.
So now I do what my parents (English, living in the US) do: stick a piece of paper to the dash, with a big arrow on it pointing to the side of the road you’re meant to be on. You may look stupid, but you’ll be safer.