At our house we just like to carve the outside of the pumpkin. That way if we do it weeks ahead of time, it won’t get moldy and gross before Halloween.
You can go to Carvingpumpkins.com to get some free patterns. Just click on patterns and hit the free link. They have some great cartoon patterns the kids will love.
Click the how to button for directions and other helpful tips. Browse the site as well, it is pretty cool.