You'll know when the buyer pays you because first off,you'll likely get an email from paypal & ebay in whatever account that's linked to your ebay & paypal accounts. Also,when you go to 'my ebay' & under 'selling',you'll see a list of items you've sold.Next to that item,there's an area where there's icons that get checked off as they happen:when the buyer completes checkout,pays you,when the item's shipped,& when feedback is given & received.So the little dollar sign icon will be filled in.
BUT that doesn't necessarily mean you get the money in your account right away.What happens is when you're new to ebay,alot of times paypal will place a hold on the money when the buyer pays you.Then,once they confirm that the item has been delivered,your money becomes available in 3 days.After that,you can leave it in your paypal account,or you can transfer it to your bank account.It still may take a few days for the money to show up in your bank account;it can vary based on your bank's policies.The longest it would take would be around 3-4 business days,but often times it doesn't take that long-with mine,when I transfer money from my paypal acct.,it usually takes about a day and a half or so.Once you get a certain amount of good feedbacks,this won't apply anymore.I don't know the exact number,but once I got a certain amount,the money was available as soon as the buyer paid,even before I shipped it.
But yeah,don't ship anything until the buyer pays you.And to get your money soonest,always provide tracking-if you print labels through ebay,it does it automatically,but lets say your printer runs out of ink (happened to me) & you can't & have to run it to the post office.Then,you'd manually enter the tracking number.Otherwise,paypal will put a 21 day hold on the money if they can't confirm delivery,to give the buyer a chance to say if they haven't received the item.
Seller & buyer on Ebay