Loved this post! Always nice to see people converted to cycling! As everyone has said, cycling expenses really do add up - particularly at the beginning, and particularly if you're riding in the winter. But I always like to say to myself that although cycling is an expensive hobby, it's a very cheap means of transport - only walking is cheaper. So don't feel too guilty about all the cash you're spending: as you've got rid of your car, the investment will pay off very, very fast. Besides, good health is a worthwhile investment too - think of the misery and the financial cost of being ill. So get out there and buy all the stuff you need, and don't skimp on quality - you'll be glad you did!
Just a couple of points. Concerning your lock: the one you need depends on the circumstances that you leave your bike in. If you're leaving it outside the village post office for a couple of minutes, you really don't need to lug around a Krypotonite! I have two locks: one I use for little errands, another for when I'm on tour or for leaving my bike for longer periods.
Finally, as your post is for noobs, I think it's worthwhile pointing out that measuring your new bike properly is very important. Make sure you know what you're looking for, and if you don't, take someone who does: riding a bike that is the wrong size is uncomfortable and can even lead to injury.
Good luck!
