Most of the information you are asking is general bearded dragon care, things that can be learned by reading care sheets. There will of course be some differences between each caresheet but that is the benefit of reading many. You can see what has been done before and what is most commonly used. There is really no one perfect method though there are common guidelines used. The very basics are as follows:
Basking temp: 95-115 F
UVB producing light
Multivitamin
Calcium D3
crickets (no bigger than space between dragon's eyes)
mixed greens (collard greens, mustard greens, dandelion greens, endive, escarole as stables, other dark leafy greens, frozen, thawed vegetables, some fruit (non citrus) as variety. (don't use canned vegetables, use fresh or frozen. Canned vegetables are pretty much useless nutricianal wise).
Substrate: paper towel/butchers paper, newsprint for babies, washed playsand, repti carpet, plastic tablecloth or shelf liner (the last three can be used with babies as well) for juveniles (12" or larger) and older.
Babies: feed 2-3 times a day appropriately sized crickets, dust with calcium and multivitamine once a day. Offer greens and/or pellets daily.
2 month - 6 months juveniles: Feed twice a day crickets and greens. Dust once every other day.
6 months - 12 months: Feed crickets once a day, greens available all day. Dust every other day.
13 months : Feed crickets 2-3 times a week, greens every day, Dust once or twice a week.
Bathing: not really required. Bath if not pooing regularly (babies typically once every day, adults couple times a week, varies alot between dragons) soaking is benefical to help them pass things along. Can also bathe if dragon dirty (tracked through poo before you can clean it up etc). Some dragons love the water and can be bathed more often to make them happy. Other dragons hate it so only do so when necessary.
The depth of the bath depends on the age of the dragon, typically no deeper than the dragon's armpit. A rolled up washcloth can be put into the tub for the dragon to rest on. Never leave your dragon unattended when soaking, just to make sure nothing happens.
Babies and Juveniles should be misted several times a day to ensure they are well hydrated. bathing can also allow them to drink if they don't seem to lick the moisture off sides of cage etc. A small dish of water can be left in the cage, some dragons will lap up water from dishes.
Silk plants are best to put in dragon enclosures, as real plants can be eaten, destroyed or just dry out from the lights. Never put any living plant in a dragon's cage unless you are 100% it is non toxic. One of the user sites already suggested in this thread as a list of what plants to use and what plants to avoid.
Dragons have teeth and can bite. However, biting isn't what they normally do. Children should always be under proper supervision when handling dragons no matter how docile they may appear. 'Your Bearded Dragons Live' by Liz Palika is a great book about bearded dragons, including how to properly handle them. Young dragons are more likely to bite or try to run away till they get used to their new owners. Each dragon is different, some are much more docile than others.
Dragons can carry parasites but most are non transmissible to humans. Hands should be washed before and after handling your dragon regardless. Salmonella, though rare with dragons, can be transmitted if hands are not washed etc. Washing and disinfecting hands, and anything used to clean a dragon's cage or pick up it's poo should be done daily as well.
That is all I can remember of your questions, but do the extra research, search for bearded dragon caresheets on google should bring up alot of resources. Take notes on what you are puzzled about or find to be different between sheets and bring them up here later for our opinions. Keep in mind some caresheets may be 10 years old, others only a few weeks so that may be one reason information differens. The more we learn and the more research done on bearded dragons, the better we are able to ensure they get the proper care.