Redgold,
Since the pattern is already pre-fabricated with established stitch lines; you'll first want to start with burnishing your edges esecially the ones that will not be bonded to any other piece of leather.
Next I would "case" the leather that you'll be tooling. I'm assuming the classes at your Tandy store had you wet the leather, transfer your pattern and start tooling once you started to see some natural color re-appear. Thats is fine for small patterns, but once you start tooling larger projects you'll want your leather to maintain even saturation. I recommend this article from Rick Jorgenson (http://jorgensonleather.com/?p=199) I would also read the forum here, and look up some youtube videos.
After you've done your tooling and allowed your leather to dry, you may dye your leather. (In the future if you decide to wet form a piece of leather in a project I would save color application for the end)
Finally install your hardware, bond & stitch your pieces together, and then give all your finished edges a final burnishing. You can apply leather sheen or Acrylic Resolene to the project for a nice hi gloss finish.
The leather in the tandy kits are great for learning and practice, so manage that expectation of your final product. In working with leather, expect to make mistakes, lots of them. Chalk those up to learning, and use them to help refine a process that you feel works best; everyone have their own process.