Alex gave you a great start for a list, but I would like to put in my .02 here...
When it comes to stitching, get yourself some egg eye harness needles (also available from Tandy and C.S.Osborn) instead of regular stitching needles. I've tried the stitching needles, and I broke every single one (the eye always breaks) in no time flat. Harness needles are extremely tough. Just be aware that there are different sizes of harness needles, and the higher the number, the smaller the eye.
For something small like those zippo cases, it might look better if you used a smaller thread and smaller needles.
Here's a source for waxed linen thread just to get you started:
http://www.royalwoodltd.com/cat14-17ar.htm
You can get different weights of thread in tons of different colors, and you don't have to pay as much as if you were to buy a 1lb. ball of unwaxed thread from here:
http://campbell-bosworth.com/catalog/index...e2d4987195ad393
If you write to (email), or call C.S. Osborn, they will send you a catalog and a list of suppliers where you can purchase leather tools, including different sized harness needles.
Just tell them that you want a catalog for leather tools.
Here's what a harness needle looks like:
http://www.csosborne.com/no517.htm
Also, if you go through old posts in the "Sewing Leather" forum here on Leatherworker.net, you will find lots of useful information.
Enjoy your hobby!
Hilly