This guide is written under the assumption that you already have a PayPal account and also a usable bank account to put funds into.
If your desired bank account has already been linked to your PayPal account then you can skip this paragraph, as this is a guide for linking your desired external bank account to your PayPal account. After you have successfully logged in and at the main page, navigate to the "Profiles" tab by clicking on the link. The profiles tab should be on the extreme right under "Auction tools". Then you will be presented with a list of options about your personal details that you can change. Under the "Financial information" column, there should be a link named "Bank account" under "Credit/debit cards". Click on that and you will be presented with a table of all the accounts that are currently linked to your PayPal account. There should be a few buttons under the table called, "Make Primary", "Remove" and "Add". The "Make primary" button allows the user to set a default bank account to use if they have multiple linked accounts, if not the only linked bank account will be automatically set to primary. Click on the add button and then you will be prompted to enter your bank account details. A word of caution here, you MUST enter ALL details as they appear on your bank account statement, if you misspelt your name or any other detail your transfer will bounce and a fee be charged. Depending on where you are in the world there are different methods for confirming and verifying your bank account. In Australia, PayPal will send two small amounts between 1 to 20 cents. These two amounts will become your verification code. After you have entered your code, your bank account will be verified and you are ready to go.
If you want to transfer funds from your nominated bank account into your PayPal account, then navigate to the "Add funds" tab which should be located next to the "Overview" tab on the left side of the menu bar after you have successfully logged in. In the "Add funds" tab you should be presented with an options table. Please note that transfers from a bank account to PayPal will take around 5-7 business days and are absolutely FREE for ANY amount. From personal experience transfers take 6 days. After you have clicked on the link that says "Transfer Funds From a Bank Account" you should be taken to the electronic transfer page and there should be a drop down box to choose your source and the amount you want to transfer. Then you just have to confirm and the process has started. Wait 5-7 business days and you should see the amount in displayed in your PayPal account.
If you want to withdraw funds from your PayPal account to your nominated bank account, navigate to the "Withdraw" tab which should be between the "Add funds" tab and "History" tab. You will be presented with an options table. Transfers from PayPal to ANY US bank are FREE for ANY amount and takes around three to four working days. Transfers to non-US bank will incur a fee if the withdrawal amount is below a certain threshold. For Australia, the threshold is $AU150, any amount below that will incur a fee of $AU1 while any amount equal or exceeding that will be FREE. It will take a bit longer for transfers outside of the US five to seven working days. When you are ready just click "transfer funds to your bank account", enter the amount, choose your destination and hit "continue" then confirm it.
You can now transfer funds between your bank account and PayPal account will ease. Let me assure all new users of PayPal, the process is absolutely safe and in the unlike event that anything adverse do happen to your account, the staff at PayPal are very helpful. I had experience an attempted hijacking of my account before and the Staff resolved the matter very quickly. I accessed my PayPal account in a public computer and so my detail may have been compromised from there. So a word of advice for new PayPal users out there, it's preferable to access your PayPal account from your own personal computer at home, the risk of your information leaking out is far less than using a public computer.