No, Linksys are a very good company. Your router is at 168.0.0.1 (or is it 169 ... can't recall off the top of my head -- also you can configure it, that's the default). You'll need your account and password (there is a default for this, too: admin and password, IIRC).
You should know all this, from when you set the router up.
I would hasten to caution you to change your account and password, too, and (if possible) only allow access from a cable and not via wireless (for added security). Otherwise any war-dialer travelling past your neighbourhood will be able to change your router setup, and steal your bandwidth.
Your WEP setup is on one of the configuration pages.