William, you will have to do the background check/transfer like you would if you were buying it from a local dealer. The FFL dealer/gunshop will charge for the transfer, the price varies depending on who you use but they are normally $20-$50. My local shop charges $20 if the firearms bought online and $5 if you buy the firearm directly from him for the transfer. It's pretty much the same as buying one from a in person store but your buying it and having it shipped. If you pass the background check the FFL will transfer it to you and you get to take it home. If for some reason you fail the background check the FFL would arrange to ship it back to buds and you would be refunded. Hope this helps.

William, you will need gov't issued ID, fill out form 4473, then your FFL will run your background check. The gun will be transferred to you upon passing the check. Depending on the state you live, you may also need a FID or FOID card, (Firearms ID card, which is basically a permission slip from the gov't to exercise your 2nd amendment right) and/or a handgun permit. Have a great day!

Once your FFL alerts you that your firearm has arrived for you to pick up you can proceed with filling out your 4473 form and they will run a background check there.
As mentioned, you will need proper identification and will have to pay a transfer fee providing you pass the BG check. And yes, if you're picking up a pistol you "may" need a permit to purchase if you live in a state that requires one like here in NY. Or even worse, IF you're in NY and want a Semi-Auto rifle you'd need a permit for that! Yup, in NY now you need one unless it's a shotgun or bolt action rifle purchase.

You will have to submit a background check at the FFL. Then the FFL gives you the firearm.