Spilled coffee on it

Sorry to hear that! The most important thing, if it is still wet, is to absolutely avoid turning it on. I would follow the iFixit guide for MacBook topcase replacement, and open it up to the point that you can get inside the main part of the laptop. I generally use q-tips dipped in rubbing alcohol for cleanup. If the keyboard got wet, it may still end up working, although sometimes liquid-damaged keyboards have a "crunchy" feel from that point on. If a key is particularly bad, you can literally pull the key off, wipe down the components with cleaner or alcohol, and snap the key back in, and that sometimes helps, but the grimy residue that coffee and soda leaves is not easy to be rid of, which is why I'd recommend popping the topcase now.

Again, it's VERY important that it is completely dry before risking turning it on. If there is any doubt about liquid still in the machine, let it sit for a couple days if necessary.

Whoops, I just realized this may be an iBook, not a MacBook. In that case, I'd follow the iFixit instructions for removing the battery, and getting inside the memory compartment, and clean out as much as you can reach from there, and then let dry. You can do more surgery if you're up to it by following the iBook hard drive removal guide until you have the machine open, but opening an iBook is considerably more difficult than popping the top on a MacBook.