What is the go to uvb fixture you like?-Anything that holds a Reptisun 10.0 bulb, reflects down, and covers about half your cage.
What is your favorite substrate?-When my girl was younger paper towels worked great (you can fit any size tank and just replace what gets pooped on) but now I have her on ceramic tile. DO NOT get sand for a young dragon as it can't be digested and causes impaction
Do you keep water in the tank all the time?-I do not, most beardies won't drink from still water, they get enough from their food and baths. A water dish will only really impact humidity (which should never go above 50%)
How do you feed your dragon? How much do they eat?- This changes as they grow up, but I use live crickets and feed her twice a day. Monitor your dragons weight and shape to gauge if you're feeding enough. It is vague I know, but I could only learn to gauge through experience. Hand feeding really helps bonding but can result in your beardie refusing to hunt if you do it too often. As far as veggies I always have them available and frequently reference:
http://www.beautifuldragons.com/Nutrition.html