Well, I say don't tell her.
First, just get to know her. A guy and a girl can just be friends. ;] Build a strong foundation for your relationship first. That way, if you find out you like her just as a friend and not so much romanticly you aren't stuck and there aren't any hard feelings. Chances are it's just a crush that will pass by fairly quickly but if you tell her you put your relationship in jepardy. Once you both have a great relatioship that won't crumble over something little, you both are older and you both are ready to date then everything is laid out for ya'.
Start out just as friends- take it slow. Seriously, it could save your friendship. ;]