I've visited the United Kingdom three times, living there for several months during one of the times. I love the city -- if you like any big city, you'll get along with London.

The Tube will get you anywhere. It's excellent and easy to use. The clothes -- everyone says you don't want to look like a tourist -- but if you've got a camera attached to your face and you're head is pointed in the general direction of up and gawking... you look like a tourist. It's not a big deal. Wear comfy shoes, because you will be walking everywhere. Have a light jacket of some sort -- for breezy mornings and nights and/or rain.

The food isn't horrible, despite what everyone says. The great thing about London is that it's made up of just about every culture all within arm's reach of the other -- so you've got a lot to pick from. It's a great place to try out different foods -- African, Indian, etc. The thing about the "fast food" restaurants over there is that it just tastes different, not bad different, just different! Just like the ketchup tastes different. It's coming from a different source. I recommend trying pub food. There are touristy-type pubs that are less intimidating to walk into. English food is not disgusting. I love their traditional breakfasts, pastries are delicious and I love tea. Fish and chips is an excellent meal. Shepherd’s Pie is an interesting thing too. The English like their potatoes and breading. And, for easy and cheap lunches, deli-type shops with pre-made sandwiches are everywhere. Visit a Sainsbury's (their large grocery store chain) and pick up snacks and drinks for the week. There are smaller grocery stores and stands with fresh fruit and small hot-plate foods everywhere in between.

As far as seeing the sites:

If you go to the Tower of London, plan on getting there early, like 9 am, and definitely follow one of the Yeoman tours -- they're a lot of fun and very informative. The Crown Jewels are impressive to see up close. I highly recommend going next door (and up) the Tower Bridge (that's the famous bridge that everyone thinks is London Bridge!) Observation deck. You can just skip the tour if you want and go straight up to the walk way -- great views of London and the Thames.

Also, if you go to St. Paul's Cathedral -- take the time and energy to walk up to the dome. It's a very long hike through a very wide spiraling incline to the first level. From there, you climb steps, sometimes within narrow walls and sometimes staircases. You can see the three levels -- the one inside with the "whispering wall" overlooking the nave and floor of the cathedral, and two outside: the first outdoor one being very spacious and restrictive as far as high walls around you. the second, tip-top one rather narrow and just with the stone wall about elbow height or so -- it's really worth it to go all the way up to the top for spectacular views of the city.

The "Docklands" area is an interesting place, from an architectural viewpoint. And, it's on the way to Greenwich for the Royal Observatory and the Prime Meridian Line.

If you're interested in Churchill/World War II stuff -- visit the Cabinet War rooms (where his command post operated from) or the Imperial War Museum (for the "blitz experience" -- which recreates a bunker you walk through using all your senses).

The Transport Museum is a cool place -- especially for buying cool Tube posters/post cards that you'll see around the underground. On the edge of Covent Garden -- which you'll most likely be visiting anyway. Covent Garden has a lot of great shops, and a small art-dealer market where you can find a lot of nice stuff. The buskers (or street performers) are always out and about, which is very entertaining.

The Tate Britain is my favorite museum (the Turner paintings collection) because the V&A and British Museums are just too overwhelmingly big (but, they do have some great stuff too -- if you have the time, visit them). V&A, among many other things, has a section devoted to fashion and a section of miniature paintings which are unique. The British Museum has a great "mummy" section, excellent Greek and Roman artifacts, the Rosetta Stone, and a wonderful library with all sorts of hand-painted manuscripts to look at.

Make sure to walk through the parks. You can rent a chair for very cheap for as long as you want, to just hang out for a rest. My favorite walking route is to start at Kensington Palace, walk along Kensington Gardens to The Serpentine through Hyde Park, along the side of Buckingham Palace through Green Park, up through St. James Palace, down the Mall back to the front of Buckingham Palace, through St. James Park, then down toward Westminster Abbey, Parliament and Big Ben. It's a long, long way to walk, but a great way to see a lot of stuff!

The changing of the guard at the Palace is mainly just impressive to see such a spectacle. Otherwise, there are better things to do. You can visit the place where they keep the Royal horses and carriages and what-not, I think it's called the Royal Mews (I've wanted to visit, but haven't.)

If you go to Westminster Abbey for a tour, you don't really need the audio -- the pamphlet and/or a tourist-guide book is enough.

Covent Garden and Piccadilly Circus are good for people watching.

Any street named so-and-so "high street" is where you'll find all the local's shopping -- department stores, etc -- as opposed to the cheesy tourist shops.

You can go into posh Notting Hill for the Portobello Road market.

Harrod's Department Store is unreal. Be sure to not look too slouchy -- they have some standards. And, they're real snobby about having backpacks. For instance, once I visited with wearing both straps for my backpack, and the guard made me carry the bag with the one strap. It's easy to get lost inside the many floors and stores. Highlights to see would be the food level, the toy department, any expensive jewelry you'd like to peruse and the souvenir department. Also, they have a small shrine to Dodi and Diana.

Theatre is a must-see if you have the time. There are tons to pick from, you can queue for tickets at the "half-price" booth or go to the box office the day of, before the show is starting to see if they have any seats available.

You can also attend a Parliament session at night -- You must sign a couple papers, go through metal detection and then you get to sit above the main floor with a great view of what's going on below. It's rather amusing to see and boring -- when I visited, several members were stretched out on their pews taking a rest. Very informal and inappropriate!

If you leave the city and venture out:

Windsor Castle is just outside of London. It's huge! You can see the doll house collection which is really endearing. And, very close by is the popular school, Eton.

I really liked Hampton Court Palace, home of Henry the VIII. It's a short ride outside of London. The Palace surroundings are beautiful, the garden is amazing and the hedge maze is a lot of fun.

Dover is a really beautiful spot (for the White Cliffs); but, if you're going to Paris (and, you should), you'll see it via the Ferry or the EuroStar on your way over or under the Channel.

Stratford-upon-Avon is all about Shakespeare -- his birthplace, where he's buried and Anne Hathaway's (his wife) cottage. It's all cute to see (and, very weird because everything is made for such short people!), but I mainly enjoy seeing the countryside around it all.

The Cotswalds are absolutely breath taking.

Stonehenge is impressive because it's so famous, that it's really neat to actually see in person. You don't get to go up and touch the stones, except under special circumstances. The scones at the gift shop bakery are worth the trip alone! You get to see sheep up close and personal too.

Salisbury Cathedral is impressive. The stain-glass is amazing. Canterbury Cathedral is equally impressive.

Bath is a beautiful city to explore (but I think the Roman Baths tour is a waste of time and boring).

If you have time, the Lake District is in north England, very close to the Scotland border. It's beautiful area surrounded by lakes and mountains. A cute bed and breakfast makes it a perfect visit, but be prepared to walk a lot. It's a great place for hiking.

Scotland is amazing! Edinburgh and all surrounding is impressive and it stays dusk outside until close to midnight. St. Andrews is very windy and posh -- it's got a beautiful golf course right on the sea; the town is quaint. Stirling and all that is William Wallace is neat to see -- again, it's the countryside that is so impressive and beautiful.