I absolutely love bearded dragons, I've had atleast 30 different ones..
You DEFINITELY need to have a nice cool spot for him to cool off, they open their mouths and stick their tongues out just slightly like a dog to cool off, if they do manually move it (hate to say it, but some are just too stupid; just like humans it's the luck of the draw) to a cooler spot, but NEVER try to put it in the fridge or something..
you can give them a nice soaking in the sink with luke warm water to help loosen up stuck skin, but be careful, most beardies will poop when they come in contact with water, so it's not recommended to have a water dish with your beardie, as they will use it as a toilet, and if you have more than one and don't catch it, they'll drink from it.
Instead feed lots of leavy green veggies, baby carrots (sliced, thin, not chopped), crickets, and the occasional wax worm. Try not to feed it any meal worms, as their shells are quite tough and hard to digest. The occasional pinkie mouse or if your beardie is large enough (mine were), a hopper or even a small mouse. I prefer feeding it live mice, but if you're not into that kinda thing you can buy frozen pinkies, or even just spritz their food with liquid reptile vitamins.
Make sure you have wood chunks, or dried grape vines, etc for them to climb on, avoid sandy substrates, unless they're edible; as they can get impacted in your beardie's colon and lead to starvation and eventually death. It's not necessary, but you can also have an under-tank heating pad, or a small heat rock for belly-heat. You must also have a UVB lamp to ensure proper calcium digestion. Failure to do so can lead to all kinds of metabolic bone diseases and criple your poor dragon...
Bobbing is a male thing, and when accompanied with a black "beard" (how they got their names), then the make is being aggressive, or wants to mate, in which case if he's with another male, he will usually attack or fight, so it's recommended to separate any males after they start exhibiting such behavior. However you can have as many females in there as you'd like. Females and juveniles will usually "wave". Females as a sign of submission, and juveniles as a sign of communication. Males will occassionally wave, but only when they don't want to fight, or they submit, in which case they'll bob up and down slightly, yet quickly and then haul ass out of there, so make sure you have them in their tanks, unless you want to move the couch or the fridge if he runs under there...
ONE THING you must remember is NEVER EVER keep different sized beardies in the same tank. If a baby is small enough, he WILL GET EATEN; cannibalism with smaller beardies is their one fault in my eyes. Otherwise, feed your dragons, clean their tanks and pay attention to them, and you'll love them. They each have their own personallity and their own traits. The more they are handled the nicer they will be. They will even rest on your arm, on a window, or hang out with the family dog. My beardies (Except one) always loved to be petted like a dog and hand fed, so you can also do the same. Any other questions, just feel free to ask..
enjoy!