I teach AHA (American Heart Association) First-Aid & CPR classes. I've also taken a Red-Cross First Aid Class at my community college (3 years ago). I think you should check out the American Heart Association website - they have tons of great info on many topics, one of which is A-Fib.
Also, something to keep in mind is that not everyone with A-fib is on coumadin. My mother was diagnosed with A-fib 10 years ago and has NEVER taken coumadin or anything like it. She has "controlled A-fib" meaning she is on meds to control the rate, and is functioning well.
There are several A-fib websites with lots of great info as well. But if your paper is about controlling bleeding in A-fib patients I don't think you're going to have alot of information. Basically anyone on coumadin will (similar to what previous posters have stated) need to get their blood checked periodically - to check their clotting time. These patients would need to be careful what food they eat (nothing with lots of Vit K which would negate their meds), be careful shaving, and be ordered to quit taking their coumadin a set amount of time before any surgery (to prevent severe blood loss). Other than that, the patient would lead a "normal" life. Perhaps you should pick something else related to A-fib - like how it can be related to Pulmonary Embolism and that's why patients take coumadin, and what that involves in their life, etc. Just a thought.
Good Luck on your paper & God Bless!