I'm not an expert by any means, although I will try and answer. You say that you have "RJ45 for the desktops" which allows me to assume that you were going to connect them both to the router with cable? If so this is not necessary. You do not need to connect any of the pc's using wires as both should connect wirelessly to the router, if you have got wireless adoptors for each PC.
Your AOL's Silver broadband should work fine with the router and it would simply be a case of plugging the ADSL cable into the router and entering the account username and password.
Then assuming thats ok, you should set up Wireless Encryption to protect your security. I'm sure other members have written guides on how to do this. WPA is the most secure option to use.
Then assuming everything is ok, run the windows xp network wizzard to set up the network.