If you came across this post while looking for info on cohabitating bearded dragons and hermit crabs, find out here why this would be a bad idea.
This is my bearded dragon Ruebe, an eight year old male Pogona vitticeps. There are seven species of bearded dragons, but P. vitticeps along with the smaller P. henrylawsoni are the two usually kept as pets.
They are friendly lizards are usually are really tame, but they need lots of room and lots of light. If you want to keep a bearded dragon, prepare for a marked rise in your electricity bill because one fluorescent tube and a heat spot just isn't enough. Think heat spot, UV light and really bright HQI or other metal halide lamps in at least a 100 gallon tank for a single dragon. You often read a recommendation for a 50 gallon as a minimum, but in my opinion that's way too small. Ruebe lives in a homemade 340 gallon (8x2.5x4 ft long, wide and high) and he certainly uses all that room and loves to run and climb.
Adult dragons eat mainly leafy greens and vegetables and only about 20-30% insects, with juveniles it's just the other way around. Ruebe gets a variety of insects (roaches, crickets, locusts ect.) twice a week and veggies the rest of the time, with the occasional diet day. He loves red and especially yellow flowers like pansies and nasturtiums.
I got him when he was year old from friends who had bought two dragons who both turned out to be male. That is not a good combination since males will fight once they have reached maturity. P. vitticeps is mainly solitary in the wild, but in captivity you can keep a male with two or more females if you have enough room (and a spare tank in case they don't get along, which can happen even after a time of living together peacefully). It's nothing I would recommend for a beginner, though, since it's easy to miss the signs of stress in case they don't get along too well. Oh, and all dragons must be the same size because they are well known for eating other lizards up to 2/3 their own size...
Here you can see why they are called bearded dragons. That's a sign of dominace and Ruebe does it almost every morning, along with nodding vigorously at us to show us that he's the dominant dragon in the house. If the dragon is stressed or angry, the beard can turn pitch black.
They can change their overall colour, too. Ruebe is a dark grey in the morning when he's still cold and often turns almost white once he has warmed up.
If you plan to get a dragon yourself, here are some websites that will help you getting set up for your new pet:
Bearded Dragon.org - full of informative articles, with a very active forum. A good place to start looking for a dragon instead of a pet shop - there are many dragons looking for new homes.
Tosney's Bearded Dragon Care more helpful articles, especially the stuff on brumation
Iguana Den is meant for Green Iguanas, but it's an excellent source of information about what greens and veggies to feed to your dragon
anapsid.org is THE website for any reptile owner, it has a ton of information of any subject you can think of including a list of herp vets, which is really important - normal vets have no clue what to do with a sick reptile