Set it up through the phone then it can check automatically at different intervals. It works great!
Set it up under the mail setting under add email, then choose AOL and follow the prompts. Just keep in mind that if you read a message, it also shows read when you check from a computer later. Anything with attachments or something important in the text, i save to the saved mail folder while i have the message open, then i can find it easier on my computer later and can download and print.
Also works the same way if you delete from your iPhone - your message will be deleted for good. My blackjack only deleted it from my phone and i could still find it as new on aol on a computer. It took deleting two important messages to find this out!
Home screen - click settings - click mail - on top of mail settings screen is add account,click that. After that, click the AOL icon and you can't mess it up, it walks you through it. This is assuming you already have an AOL account.