Welcome to the forums!
The info you find here won't steer you wrong
And here's a nice big list lol. I actually stole and modified it from an awesome gal (username OnlyMediocre), so the credit should go to her. But she's covered all the bases so I thought I'd use it!
Tank- A 20 gal will work for a baby; no less than a 40 gal breeder for an adult
Basking (Heat) Bulb/Fixture- you can use a regular incandescent household bulb instead of paying $20 for a "basking" bulb at a pet store. Clear or Bright White are the best. If you do get a pet store basking bulb, make sure it is not coated with Neodymium.
UVB Light/Fixture- UVB rays are super super important. Without the right UVB source a dragon will not survive. There are quite a few out there, but the ReptiSUN 10.0 or Arcadia 12% tube bulbs are the only ones proven safe for bearded dragons. No coils or compacts! (Also make sure that it's a ReptiSun and not a ReptiGlo). You can get a cheap T8 sized fixture for your ReptiSun or Arcadia at any WalMart or home improvement type store. Your UVB tube should be run at least half the length of your viv, but preferably 2/3rds or longer. Your beardie will need to be able to get 6-8" away from a ReptiSun, and about 12" away from an Arcadia (I think, may want to double check distances). It's best to mount or hang the UVB inside of the viv, since glass blocks 100% of UVB rays and screen blocks 30 to 50%.
*You can also use a MVB (Mercury Vapor Bulb), those are heat + UVB all in one. The safe MVB to use is PowerSun.
Substrate- Use tile, reptile carpet, non adhesive shelf liner, newspapers, or paper towels. No sand, woodchips, or anything loose that they could ingest. Even if the packaging claims it's digestible (cuz in all reality it probably isn't
)
Thermometer- Correct temperatures are important! Make sure to use a digital thermometer w/ probe or a temp gun, since those little dials and stick-on ones are crazy inaccurate.
Basking Spot- Anything that will let your beardie get closer to the basking light, most people use a rock or log/branch (if you get something from outside, make sure to bake or boil it to get rid of anything that may be living on/in it)
Food dishes- You'll need a dish for veggies, and a dish for live feeders. Make sure they're made of something slightly durable since you'll be changing their salad on a daily basis and giving live feeders daily as well. Multiple times per day if it's a younger dragon
Fresh greens/fruits/veggies- Also known as their daily "salad"
Here's an awesome color-coded list of what fruits/veggies to feed:
http://www.beautifuldragons.com/Nutrition.html
Live feeders- Correctly sized crickets, Phoenix worms, Dubia roaches, etc. No mealworms!! Feeding a baby is a bit pricey, and beardie food bill will be the highest bill after start-up costs.
Calcium Supplement
Multivitamin Supplement
Also: When/if you get advice from a pet store employee or owner (especially PetSmart or PetCo!), remember to take their advice with a grain of salt. If you're unsure of something, feel free to ask on here or do extra research.
Because unfortunately, pet stores are notorious for giving out inaccurate information. There are a ton of people who have bought the wrong UVB, substrate, etc, only to have to go out and get new everythings because the pet store didn't know what they were talking about.