In order to bid on eBay, you must first have a Paypal account.
If you don't have a Paypal account yet, then you can set one up by going on Paypal.com
Your account will be linked with a bank account, an email address, and an ebay moniker.
If you have a Paypal account already, then if you are wanting to bid on an ebay listing, you just simply go ahead and bid by clicking, Bid Now, and then type in the $ amount that you want to bid on the item.
Remember though, that once you enter your bid amount, you are committing to pay that bid amount, when the auction ends, if you are the winning bidder.
Do not bid unless you are indeed willing to follow through and pay. You, as a bidder/buyer have obligations, just as the Seller has obligations that they agree to when they list an item.
If you are interested in an item, but are not sure, or think that you might change your mind later, then do not bid yet. The better thing to do is to Watch the item (you can click it to put it in your Watch List) and then you can always make a final decision just before the item ends.
