An FFL is a Federal Firearms License.
If wish to purchase guns off the net or through a catalog or whatever, you have to have one. If you don't have one, you can still purchase guns but you must have the gun you wish to or have purchased sent to an FFL holder like a gun shop so that they can do the necessary transfer paperwork and background check.
The process is actually very simple.
Say you wish to buy a gun from Gunbroker or a person on the forums. Find a gun dealer in your area and ask if they can or will do transfers. Most will and usually charge a fee of anywhere from $20-$40. Once you find a dealer who does transfers, buy the gun and go back to the dealer that you wish to have the gun shipped to. They will either give you a photocopy of their FFL license to send to the seller along with your payment, or they will fax or mail it themselves to the seller, each dealer has their own preferred method.
Once the seller has received both your payment and a copy of that dealers FFL license, he will ship the gun to that gun dealer. Once the gun dealer receives the gun, you can go in, do the background check and other paperwork and voila, you now have a new gun.
