At the Beau Monde conference in Reno (which, BTW, was well-organized, informative, and lots of fun!), I did a short workshop on getting the most out of your travel for research, which seems to fit in with what current discussions on favorite museums. A few of my tips (strictly basics, but things which I wish other people had told me before I went stomping off across England the first time!) are:
1) Do all the research you can on the sites you plan to visit before you even leave home–the Internet is God’s gift to travelers!
2) Try to visit sites at “off” times, and always make a note of what time of year you are there, what the weather and surroundings are like
3) Take advantage of a good guide or docent–smother them with questions! I found that the vast majority LOVE to talk in-depth about the site and want to answer questions (even the weird ones we writers always have)
4) Don’t be afraid to explore (except where there are No Admittance signs, natch!)
5) Wear comfy shoes and leave heavy bags behind (load up at the gift shop AFTER the tour)
6) Take a camera or small notebook (a little tape recorder, if you have it)
7) Always buy guidebooks! (And, if you’re me, tea towels and figurines and magnets and other useless things)
8) Organize your info as soon as you get back to the hotel, then it’s ready to be input when you get home–label photos
9) Write off all your expenses (my CPA’s eyes light up when he sees I’ve been on a trip)

Author Diane Perkins also has an article posted online about research and travel (http://www.wetnoodleposse.com/Sept_2005/writerslife.html) that I enjoyed.

And all of this talk about museums and sites has me longing to go back to England ASAP! I have never been to the Herschel Museum, but it is now definitely on my list, and I second the Geffrye Museum. Two places I like that are a bit off the beaten path (and, strangely, they both have to do with music) are Finchcocks Living Museum of Music and the Handel House Museum

Finchcocks is in Goudhurst, Kent, a Georgian manor built in 1725. It is now owned by pianist Richard Burnett and his wife, and is a museum containing over 100 historical instruments (mostly pianos, clavichords, harpsichords, etc), the oldest dating from the early 1600s. They also have an extensive collection on eighteenth century pleasure gardens, such as Ranelagh and Vauxhall. There is a great staff there, who will happily play demonstrations on the instruments. Great fun.

The Handel House is at 25 Brook Street, Mayfair in London. It was (you guessed it) the home of Handel for over 30 years, and they have many of his possessions and original manuscripts (including one for a portion of Messiah), as well as beautifully restored Georgian rooms. The museum has expanded into the house next door, as well, and this has an exhibit on Georgian life in London that is not to be missed. On an interesting sidenote, this home was also the residence of Jimi Hendrix for a time in the 1960s, and they have a small exhibit of some of his items, which makes a fun contrast to all the Georgianness. 🙂