For the engines, make sure all the fuel is drained out of them. Pull the plug and put some light weight machine oil in the plug hole and through the carb. Make sure the oil works its way to all the bearings and other moving parts. Put the plug back in and put something in the carb to keep dust out. In the spring, remove the plug and whatever you put in the carb, put a piece of cloth over the plug hole, and give it a quick spin with a starter to blow the oil out. Put the plug back in, or install a new one, fuel it up, set the needle a bit rich and it should start right up.

Unplug the battery packs. Discharge them to 1.1v per cell and don't worry about them til spring. Red's R/C battery clinic has a great article covering the details: http://www.rcbatteryclinic.com/