Ditto on the clean litterbox, good food, early spaying, no declawing, and posting pictures on GC. If you really can't handle cats with claws, try
SoftPaws.
Make sure that you keep collars & tags on them, even if they're "only" inside cats. Even only-inside cats escape sometimes. Also consider getting them microchipped. It's relatively inexpensive (usually less than $50/animal) and can save their lives if they should escape. Talk to your vet or the local humane society.
Most importantly, DO NOT let them nibble or bite on your hands/fingers. It may seem cute when they're kittens, but it is a bad habit for them to get into. If you're playing with them or petting them and they start doing that, say "NO!" immediately, then disengage. Stop playing and IGNORE the cat for at least five minutes. If that doesn't work, then hit them with a squirt gun. That's the only way they'll learn.
Have you decided on names yet?