Hi Dave, and welcome to CF
If you're really lucky the issue might be just a case of re-seating the keyboard connector - depending on the machine they can be a right pain to connect correctly.
I will be honest, the long term prognosis for the laptop might not be so great - liquid spills can appear to be fine at first but without ultrasonically cleaning every component (and even then your chances may vary) you might find the machine starts to fail in lots of weird and wonderful ways.
I lost my Blackberry in a similar fashion - it worked great for a week, then I was unable to move around on the phone, and eventually it died altogether.
My advice here, at least as a first action, would be to use an external keyboard to access the laptop and backup your data and either think about a new machine, or finding out how much it would cost to replace the mainboard.
If you fancy your chances the next best thing would be to take the bottom portion of the machine to bits, disconnect the battery and spray liberally with a PCB safe contact cleaner. It would be worth seperating the mainboard from the bottom chassis in case any liquid has pooled around here.
I'd advise paying particular attention to the keyboard connector (usually a ribbon cable) as this appears to be where you might having issues.