This info taken from bettafish.com - please check them out if you need more info - they really do have a ton of helpful folks.
*Symptoms: Can be found by shining a flashlight on your betta. If it looks like it is covered in fine gold of rust colored dust then it has velvet. Clamped Fins, no appetite, darting/rubbing, loss of color, lethargic
*Treatment: It is very contagious so you should treat the entire tank. Treat as you would treat Ick. Potassium Permanganate is also my favorite for treating Velvet.