You should just get yourself a nice piece of masonite and let the wife know that sometimes you will be soldering on the kitchen table! She will get over it.... maybe. Mine did.
I agree that instructables.com is a great place to start!
There are so many resources available, just try to think up a problem that you want to solve and see if you can use the arduino to solve it....then go!
If you are near to a Makerfaire absolutely go to it!!