Ben, get a book like "How to model Military Vehicles"--look on either half.com, ebay, or amazon.com--use the search and you should be able to find something; there are quite a lot of good available books out there that can take you through all of these steps. I might also recommend ARMOR magazine, available through Squadron--they also have a bunch of really excellently detailed tutorials on weathering.
There's just too much you need to know for any one guy to post here! That's quite an order! You can also learn a lot by browsing the armor forum too; don't be afraid to go back quite a few pages, even like 20-30.