I may have missed it in all the comments, however, in addition to the dies, you need a shell holder for different cartridges. Some of the Lee die sets include the shell holder, otherwise you get them separately for 6-10 bucks each.
Assuming you get a Rockchucker, you can prime cases on press. However, consider that it is much slower to do it that way, instead of using a tool such as the Lee Autoprime, or RCBS Universal tool.
For straight case pistol brass, get Carbide dies to avoid having to lube the cases. Bottle neck rifle brass needs to be lubed prior to sizing (even if the die set says carbide).
You say you may be loading hundreds. Consider your time. You may average 50 rounds per hour, using batch processing and the single stage press. By Batch processing I mean: lube brass (if necessary - see above), size/deprime all your brass, then prime all of them, then measure powder for each, then seat bullet, then crimp. You can seat/crimp in the same step, but most folks like to do that in two steps.
Read the books first. Several have good reloading sections in them, e.g. Lyman, Lee, Speer, ABCs of reloading, etc.
Welcome to the reloading world. And - ask questions.