It's cool that you're coming to the UK. There's a lot to see and do, too much to cover here but I'll give you a few of my thoughts.
I'm Scottish but I've lived in London for four years. I like it here a lot. It's a fantastic city, with people from all over the world. Definitely worth spending a bit of time here. As to where to eat, there's a million restaurants, but I'd recommend an evening on
Edgware Road for Persian / Middle Eastern food or
Brick Lane for South Indian / Bangladeshi.
Time Out has long been a source of credible reviews.
If you like rock / metal Camden Town is the place to hang out. There's a great market at the weekend and most of London's best rock venues are around this area. Ok, it's a magnet for pierced and tattooed tourists from far and wide and can be very busy, but definitely worth a visit if that's your scene.
You'll find a few lapdancing bars and strip clubs in the central London area of
Soho, but I'd recommend
Hackney Road / Shoreditch High Street. There's a few to visit within easy walking distance of one another. It's pretty straightforward and safe to hook up with working girls here too. A Google search for London escort agencies will bring up a ton of matches. Punternet is a source of information.
You sound like you'd appreciate The
Hunterian Museum at the Royal College of Surgeons.
Jack The Ripper was big around these parts. There's walking tours around the sites of his murders which might be kinda fun. I'm sure there's a ton of haunted places to visit around London. A lot of torturing and murdering has gone own here in the dim and distant past!
I wouldn't recommend hiring a car while you're in London. I haven't felt the need to own one in three years. Public transport is excellent here. Just buy an
Oyster Card. TfL's website is good for planning getting around. Don't be afraid to use buses. You get to see a lot more from the top deck.
I enjoyed Stonehenge. I didn't intend to go there, I had been to Exeter to buy a car and I just I just happened to be passing it on the way back to London. I can understand Bawksy saying that it should be bigger. You can't get very close to the stones so it's hard to get the full impact. I rolled a spliff and went for a walk. You get a great view if you take the time to get a little further back.
It's very true that trains can be expensive here, particularly when you don't book well in advance. A cheaper alternative are
National Express or
Megabus coaches. Hiring a car is probably good idea for getting around more rural places, particularly in Scotland.
My tips for places to go in Scotland would include a visit to Glasgow and Edinburgh. Also, I don't think you can beat the western highlands and islands of Scotland, particularly The Isle of Skye.