It seems I keep giving the same advice so thought I'd put it on here ... I would say if visiting the UK do drive Britain has the friendliest drivers anywhere in the world and you can say you conquered the left (proper) side of the road ...the three things you will need are as follows:
Phillips Navigator map. These are standard issue to certain secret govt departments because they are quite simply the best road map of the UK. They are slightly more expensive, just a couple of pounds more but massively more information and at a scale that is perfect. They also have speed camera details and tourist information on
A good sat nav with speed camera locations. If your a frequent visitor buy a UK sat nav or you can now get them with UK and USA mapping. However, sometimes these need upgrading as soon as bought so might be worth buying in the USA prior to travel. If you decide to hire one with your hire car ensure it has speed camera locations on it.
Another point is choice of hire car. Most cars in the UK are a manual gear box type but more hire cars are automatic ensure you state your preference. Also remember in the UK even small cars can be diesel so ensure you know the type of fuel, it's normally stuck in somewhere obvious but if not ..check! Also, some roads in the lakes, Devon and Cornwall and Wales are quite narrow, so it may be worth getting a smaller car. However, Britain is a country of hedgerows so a higher SUV affords the luxury of seeing more and giving you the ability to park off road and get through those minor floods etc.
I hope that helps everyone! Any driving questions mail me !