Udapiur is a very safe and tourist-friendly town. We went in Oct-09. Most of the 3 star Hotels are close to Lake Pichola. We decided on Krishna Niwas Palace overlooking the lake. The room was not exactly as it looks on the website, it ended as soon as it started. However, most of the Hotels around are that way, since these are from the old era, reconditioned with modern amenities keeping the traditional feel intact. We could also see Sarovar (which looked good) and Natural (not that good) from outside.
Half of the sight-seeing places are close to Lake Pichola - the City Palace is 5 mins away, and Jagdish temple is close-by. One can find lots of restaurants around, the food is quite tasty. There is a roof-top restaurant exactly opposite Jagdish temple, we liked the food there. Do not miss the cultural programmes at Bagor ki Haveli in the evening.
One can do boating in Lake Pichola till Jag Mandir and sunset point. It is a nice way to relax. Also, once should go to the Maharana Pratap Smarak in the evening and relax in the park. Just opposite to it, there are lots of activities that families can enjoy- camel riding, junk food stalls, small merry-go-rounds, etc.
The Ranakpur temple and Kumbhalgarh Fort are both are along the same route - totally about 200 km to-and-fro from Pichola Lake. We took a non-a/C Indica for Rs. 1200. The temple is good, but not amazing. They do not allow wearing shorts and sleeveless tee or tops. However, they charge a reasonable 20/- and provide the necessary cover-up on lease. Kumbhalgarh Fort is good too, but there isnt much to see.. it involves a lot of walking till the top, and except for some good views from the top, there isnt much. Between Kumbhalgarh and Ranakpur, there are a couple of good buffet restaurants, the food is non-spicy and mainly for foreign tourists.
For dinner, we tried the nearby Masala restaurant and couple of other roof-tops. I have heard, the Amer Haveli is a very good restaurant.