Hi there Tracy, the short answer is yes you can.
Start the steam client, chances are it will log his profile automatically, just log out of his account and log into yours. It will ask you your password so make sure you know it before you try! Also these days you have Steam Guard as well, it'll send a code to your E-mail, just copy and paste and you're away to go. Remember you'll have to download the game you want to play as well. Hope you've got good broadband.
Good luck and post back if none of that makes sense.
Edited by Bokononist (12/11/11 03:43 PM)
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