Johnny,
There is a 200NH and a 200-20 that are both siphon feed. The -20 version has what looks like three O-rings wrapped around the handle, and one of the adjusting rings is graduated 1, 2, 3 etc. and the -NH version just has two knurled knobs. There is a difference in the kind of head, as well.
The small knob on the far rear is used to hold the needle tightly, and the large one is the adjust the needle position. Turned all the way clockwise is the smallest line and turned all the way counter-clockwise is the widest line. Somewhere in between is where you'll want to be. That's the same for both kinds, with the -20 having a graduated scale for consistancy and a non-Crown spray regulator for close up work. The needle can extend past the spray regulator, so be careful if this is your kind!
I prefer the color cups to the bottle, easier to use, fill and clean! They are also siphon fed. The gravity fed versions have fixed cups on the body.
There isn't a good reason to remove the head for cleaning, unless you've allowed paint to dry in there! If you're using acrylic paints only, this is my routine:
Rinse the color cup out with Windex, no point in spraying windexed paint through the airbrush. I usually take the cup or bottle off and rinse out, and use a Q-tip to remove excess paint from the connection on the AB body.
I use an old bleach bottle and cut an X shape large enough to poke the head of the airbrush into about 3" from the bottom to spray the cleaner into. Makes less mess this way. Take the lid off before spraying!
Fill the cup/bottle 2/3 or so full and spray until the cup/bottle is empty and repeat. Take a soft rag (or even a paper towel and carefully cover up the tip of the airbrush. You might want to pull the needle back slightly to protect it and gently spray until bubbles appear in the cup or bottle. This is called back-flushing. Then I pull the needle (loosen the small knob and pull from the rear of the brush) and check to see if it's clean. If there is paint on the needle, carefully put back and keep spraying until you don't see any paint on the needle. Then fill the cup or bottle with some distilled water and rinse out any Windex. Windex contains ammonia and that can stain the airbrush. Put a little needle lube or glycerin on the front 1/3 of the needle and put back. You now have a clean airbrush.
Badger will send you an instruction manual, though they're pretty light in information. I've got the 200-20 and I can scan those instructions for you. PM with your email address, as I can't send attachments through the FSM mail system. You might be better off contacting Badger as below:
Badger Air-Brush Co.
9128 W. Belmont Ave,
Franklin Park, IL 60131
Phone (800)AIR-BRUSH or (800)247-2787
Phone (847)678-3104
Fax (847)671-4352
For general information please E-Mail info@badgerairbrush.com