you will find information regarding diets, food pyramids, ideal weights, etc. Mayo Clinic
website has good information, also; I often use it as a reference. Check out Dr James Beckerman, here on MedHelp; he's got some really good journals that you can read.
There are also free videos that you can watch online for various exercises. Try yoga; there are a ton of videos that you don't have to pay for. Not sure if you can download them, but you can certainly watch/do them online.