Plug your laptop into a port and point your browser at
http://192.168.1.1 or perhaps
http://192.168.1.100 which should be the administration page for the router.
Check that the router has valid DNS settings, and that the wireless is correctly functioning from there (lights on the front aren't always a good indicator).
On your laptop try setting up a new wireless connection and scanning for available networks to see if it can find you're network again (rather than failing to connect to the established network settings, as "something" might have changed in the wireless networks setting by virtue of the reboot).
Make and model of the router would also facilitate more detailed advice on settings etc. (providing a manual can be found, which it probably can, I remember Jim posting a link to site that hosts manuals for virtually all wireless routers).
