I was thinking of going to Richmond to see Ham House/Marble House and the Park. Is the town interesting as well? I won't have a car, but I think I'll probably hire a bicycle. Thanks!
Laurel: Check out the Bikely.com/maps/bike-path/West London-BBCish-to-Richmond Park. Hampton Court is also near. Evidently the bike ride along the Thames from Richmond to Oxford is a favorite. You could take the train to Richmond and then rent a bike if you want to avoid urban traffic.
Richmond is an interesting small town, the main part of town is set around a big green. This area is worth a brief visit. Just off the green is the start of Richmond park- a very big open area. Has at least one small herd of deer. However the river walk, is probably more interesting
Richmond is fully absorbed into London. I wouldn't suggest cycling from central London unless you're very experienced in big-city cycling. If you aren't, you can get the Underground District Line from central London, or suburban trains from Waterloo station which will be faster if you are travelling from that area.