You won't be able to use your Broadband when away from the phone-line it is associated to. A good PAYG ISP to use while on the move is Freeuk.
You just connect to any phone point available and pay for the cost of a local call. You can connect from any number. click here
Once connected to the internet you will be able to access your AOL account by going to the AOL home page and typing in your screenname and password. j.