Here is how paypal works. There are 3 types of accounts, one individual, one business and one premium.
The first one doesn't allow you to take credit cards, but only e-Checks and money orders. The problem with it is that it takes 3-4 days for a transaction to go through, so lots of people buying from you will be pissed.
The second one allows you to take credit cards, but charges you a percentage (something like 2.99%) on each transaction.
The third account, I'm not really sure about.
Anyway I would go with a business account. Once you set this up, you need to provide a bank account to link to your paypal account. Whenever a person purchases a product from you on Ebay or anywhere else, the amount of money they pay you gets deposited in your Paypal account. To move it to your bank, there's an option to withdraw your money to your bank account and it's free.
EDIT: fov got it all already
Except for the part of having a fee to withdraw money to your bank account.
