Wipe up as much of the latex paint as you can immediately with a clean rag. Add some water to the paint if it is still fresh but not readily coming up with only a rag.
Saturate any old latex paint stains with rubbing alcohol. If you are concerned about the wood's finish, pour some rubbing alcohol onto a rag and set it on the stain.
Cover the rubbing alcohol with plastic wrap to prevent the alcohol from evaporating. Allow it to sit for 30 to 60 minutes so it can penetrate the paint.
Remove the plastic, and wipe all the alcohol away with a wet rag. The latex paint should wipe away without much effort.