I would start with one bearded dragon, they are not social animals and there are a million health reasons not to keep them together, the bottom line is: just dont do it. Look over the last few pages of posts for threads concerning housing multiple beardies together and you will see why not to house them together.
As far as care i would check out www.beautifuldragons.com, it is a great website.
Beardies are awesome pets if you have the money, time and room for them. They are easy to tame and are quite personable.
Do LOTS of research before you purchase one and make sure you have everything you need ready and set up before you get one, two weeks might not be enough time to prepare. Do not rush into getting a beardie as it may cost you your beardies health.
If you get a juvi (6inches) you can start them out in a 20gallonLong tank or a 40Breeder (I would go with the 40breeder cause it will last you longer) i wouldnt start with anything bigger than a 40B as you will probably just stress him.
Basking temps should be between 100-110degrees at the hottest point and ambient temps should be in the high 80's. They also need a UVB light that needs to be replaced every 6months and must be close enough to them that they can get within 6-10inches of it. Basking sites and hiding sites should be provided as beardies can be pretty active and like to explore (another reason why the 40B is a better idea). Adults need at least a 75gallon tank, mine is in a 90 and i want to give her more room!
Juvi's should be fed mostly (70-90%) protein in the form of silkworms, crickets, waxworms (occasionally), superworms (as they get bigger), and roaches. They should also be fed some (10-30%) veggies and fruits, although much more emphasis on the veggies than the fruits, including: collard greens, mustard greens, dandelion greens, turnip greens, endive, and escarole as staples and shredded carrots, squash, various pod peas, clover, various peppers, berries etc as "spices". Their meals should be supplemented with a straight calcium supplement every day when the are babies with reducing amounts until you are supplementing once a week to once every other week with the adults. A multivitimin supplement should also be used two or three times a week with babies and once a week to once every other week with adults.
As far as substrates go, its a much heated debate. Beardies under one year old should NEVER be housed on sand or anything they can injest, substrates such as paper towels, newspaper, tile, linelium, shelf liner, or indoor/outdoor carpeting are the only safe thing for them. Once they are older, some people choose to house them on sand, but it carries a big risk of impaction. In fact there was a thread not long ago where someones vet suggested they take their beardie off sand. Sand is also extremely hard to keep clean and bacteria harbors and grows in it. Impaction can result in death and is a risk that can be easily avoided by using a safer substrate. If sand is used it should only be fine grain, washed, screened playsand (the kind you can get at home depot) and it should be spot cleaned daily and completely changed once a week or once every other week. Calcium sand should NEVER be used. I used to have my beardie on sand but the cleaning was ardous and i was tired of hauling all the sand out and scrubbing the tank down all the time and i learned about the risks of impaction. Adults can be housed on any of the substrates juvis can, you can also try wheat bran for them.
Basically, do lots of research and be fully prepared before you bring a beardie home. They are awesome pets and if you make a careful, researched purchase, you will not be dissapointed.
Good luck

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0.1 Bearded dragon
0.1 mexican Black kingsnake
1.1 Leopard Gecko's
0.0.1 Tokay Gecko
1.0 Blue Tongue Skink
0.0.1 Reverse Okeetee Corn
0.1 Anerythristic Corn
0.0.1 Red Tegu
0.1 Bullmastiff
4.1 Cats