There's lots of info on bearded dragons available on the net, so a quick search should help you out tons. That said, I'll go ahead and give you some of the basics.
I keep my beardie in a custom built wooden cage. It's a little more than 5 feet long and about 21 inches tall and deep (front to back). It has screen doors, and I keep his basking spot between 110 and 120. Young dragons are best kept on paper towels or tiles (tiles are in my opinion the best to use, they are easy to clean and disinfect), and do better sometimes in a smaller enclosure, but it's best to start with a 40G "breeder" tank than a 10 or 20 gallon. Or, you can just start by building a wooden one and partitioning it until the dragon gets bigger and it's easier to find the food (crickets, roaches, isopods, grasshoppers, grubs, worms, etc...). Wood is a better medium for beardies because it insulates much better and the temp will be more steady. I am currently using two 60W halogen spots to heat my beardie's enclosure to the appropriate temperatures. You'd be using
at least twice that much with a glass tank.
Beardies aren't really the best to put in a vivarium, they are from the desert, though there are other reasons as well. Other than a vive being too humid (because of water the plants)the biggest reason is that they will eat any plant matter they can get in their mouths, and alot of plants are toxic. Ivy, for example, is deadly to bearded dragons. I use artificial plants with my beardie (which he also tries to eat), because he will eat or dig up anything I put in there, which is usually spineless catci or succulents. If you DO put any plants in with them, you have to research to make sure it is edible. So, in my opinion and experience, it is best to go with a plain tank with artificial plants, rather than a planted vivarium.
Beardies need lots of safe veggies to eat. When they are young they won't eat them as much and should get more protein, but you should always offer a salad. The only one that is suitable from the store pre mixed is the "spring mix" salads, preferably the one with herbs. Do NOT feed a beardie iceberg lettuce, it will give them diarrhea and has no nutritional value. If you want to buy loose greens, dandelion, mustard, kale, and collard greens are a great staple. You can do some research on other greens and veggies you can add in. you can try "beardie salad" as your search terms, that should get alot of results.
As for equipment, NEVER NEVER NEVER buy a hot rock, even if the pet store tells you you have to have one. Beardies don't need belly heat anyway, they need to bask. You'll need a good basking light, I like to use the halogen lights because they get hotter for a lower wattage. You'll also need a light to boost the ambient temp, so any bulb that gets hot and isn't a spot will be fine (don't waste your money on specialty bulbs from the pet store, just go to wal-mart and buy regular bulbs). You will need a UV source though, and you'll either have to order those online or buy them from the pet store. It is best to buy the UVB tubes, NOT the spirals. If you want to learn all about the UV lights, I recommend you check out the UV Guide UK website. It's very informative and they have researched the majority of different types of bulbs available on the market. Unless you will have the proper space to keep the distance from the bulb, do not buy a mercury vapor bulb (UV and heat in one bulb), they need to be kept fairly high above the basking spot, and most folks aren't keeping enclosures on that scale. If you have a closet to devote to your dragon it's a great choice though.
I don't really keep a water source in with my beardie, but I do give him water either from a dropper or when I bathe him (every day or two) in the sink. You won't need to mist the cage either, except occasionally when it is shedding time (and you can skip that if you are bathing him frequently).
You'll need a digital thermometer. The one we recommend the most often is the Accurite brand with the probe that you can find at wal-mart and similar stores. If you can find it, the wireless grill thermometer that has two probes and a wireless base would be perfect for a beardie enclosure (I've had my eye on those online for a while now

, but the accurite one is plenty. Do NOT waste your money on those puck meters (the stick on dials), they are highly inaccurate, you might bake your dragon or freeze him.
Beardies make great pets. They have a wonderful personality and are like the dogs of the lizard world. We bought ours for my husband, and I just love him to death. They are super easy to take care of, but I must warm you that they are little eating machines. Be expecting to buy at least crickets in bulk. You'll spend WAAAAAAAAAAAY less for them that way. Spending 10 cents or more per cricket at the pet store is going to add up VERY quickly. Young beardies have been known to eat between 20 and 50 in a sitting (depending on the size), so I'm sure you can see how that would add up! It's only about 20 dollars for 1000 crickets if you buy in bulk online (or you can breed your own).
So, take what basics I've told you and do some searching around the net, then come back and let us know if you have any more questions, ok?
Oh, and welcome to the forum, AND the hobby!