Here's what we do at my store.
We block off a path around the boat and form a line thru electronics, people just check out there like a reg cash register. Some items (such as Ipods and whatnot) are in the boat to buy and have to be bought back there so people wait in the big line for that one item
Anyhow, we have usually cashiers back there ringing up, and the rest are directing the line and pointing customers to where items are. there is one person standing on the isle side of the boat to answer questions and directing people not to ask the cashiers and to ask them. and the cashiers are instructed they cannot answer questions and to tell them to find other people to help em
What other stores do is probably a bit different..