Bella gets a bath about every 2 weeks (now that she doesn't go outside that often because its already cold here in Ohio), but during the summer when she played outside everday I gave her baths every week. I use a lot of skin conditioning sprays on her between baths to make sure that she doesn't dry out and keep her baby powder fresh.
lol. I also put a heavy conditioner on her each time she gets a bath and I make sure that she is rinsed VERY VERY VERY well. And I have yet to have any problems with her drying out.