Don't use factory ammo as your guide. Use the book. OAL is based upon the particular bullet style / weight, and the powder charges are formulated accordingly.
You may want to see if you can find a periodical as well. Hodgdon publishes an annual reloading journal with current information. Use 2-4 sources to help "triangulate" toward the right solution.
My only recommendation on equipment would be a balance scale to compliment your digital one. Digital scales can be finicky - sensitive to temperature, other electrical devices (lights, esp. fluorescents), drafts, and level.
Use both scales until you are confident with your digital one. Some have ha success putting their scale in a cardboard box when reloading in a drafty place like a garage.
You may want to get a can of Hornady One Shot case lube. It worked much better for me when resizing rifle brass than the standard lube pad.