sgirglani, I like both the Jai Mahal & Rambaugh Palace in Jaipur - it really does boil down to what price range you're looking for. The Taj Umaid Bhavan Palace in Jodhpur is, IMO, the best place to stay there, its an amazing experience.

For sightseeing, I suggest you call Taj Holidays (or check out their website). For example, both their Jaipur hotels (Jai Mahal & Rambaugh) offer a 2 or 3 night package with airport/train transfer, half board & sightseeing by a/c car with a guide included. Sightseeing in Jaipur is pretty standard, Amber Palace, the city palace, Hawa Mahal, Jantar Mantar etc.

Taj also offers some Rajasthan packages for as many days as you want in the various cities, with a car & driver to get you between locations & take you sightseeing. It may be easier to simply book a package through them than to deal with all the hotels separately, particularly if you also decide to do the Udaipur Lake Palace hotel (also a Taj property as are the three I list above).