Disassemble as much as possible, leave to dry in a warm, dry place for a few days to a week (sometimes more depending on where it's got to). Make sure you leave it upside down, or the opposite direction to the entry of the liquid. Take the battery out straight away. If the hard drive isn't wet at this stage, take this opportunity to plug it into a PC and back it up.
Once dry, see if you can find where it got to inside if you don't know already, and use some isopropyl alcohol to clean off any residues on PCBs and connectors etc. Once it's all dry, plug it in and try turning it on. Any signs of trouble, take it to an expert to see if it can be completely diagnosed and fixed should it be financially sensible.