Have a look in some of the supermarkets, we got a great kit a few years ago with loads of great designs and some fab tools to make it easier, but if you cant find anything, then I'd suggest cutting the top off at an angle (so it sits back on when you put it back), use a short sharp knife to cut it, a spoon to scoop out the flesh and I'd not do it more than a day or so before you want to display it, as they tend to turn to mush quite quickly once hollowed and cut out!
I've never had a problem with using a nightlight even just a few minutes after carving, so dont worry about the flesh being too wet, it isnt IMHO!
Another tip we've used iis to display the finished and illuminated pumpkin in a wire hanging basket, from even a few feet you cant see the basket at night and it appears as though your glowing pumpkin is floating!
Hope this all helps! I love pumpkins and carving them, always have at least 3 done and the whole house decorated for Halloween / Samhain!