I've spent my Friday evening drinking blue moon, listening to Glee and buying crap on eBay... I decided to try and blow into my beer bottle to make it whistle which made it bubble over all over my damn bed and keyboard. Now my silly left clicker key is sticking.
I hate to be the bearer of bad news, but you likely won't get that 100% clean. If you feel really comfortable with taking your device (I'm assuming it's a laptop) apart, you can attempt to clean some of the mess with distilled (not tap) water or high-concentration rubbing alcohol (the higher, the better) and then leaving it apart for a while to completely dry. If you feel comfortable with taking it apart but not with the extra liquids, I recommend you start searching eBay for replacement parts. If you're not comfortable with either of those options, you might want to consult a nearby computer repair/service center for a quote (or the manufacturer - though most don't cover spill damage under warranty and will likely charge you almost as much as a new laptop for a repair).
For everyone's reference, if you spill liquid into a keyboard or laptop, you should flip it upside-down immediately (but gently) to minimize the damage. Turn it off, disconnect any cables, and remove all sources of power, if possible, and allow ample time for the fluid to drain off before attempting to clean it with distilled water and rubbing alcohol. If the device is small enough, you might also be able to wick the moisture out of it by sealing it in a large Ziploc bag or Tupperware container filled with white rice.