I use a MEC 600 Jr. to reload my 28ga. hulls. I buy my supplies from Graf and Sons by mail.
You'll be surprised at how much more "relaxed" shotshell loading is compared to metallic cartridge reloading. Decide what loads you want and try to standardize your hulls, wads and primers. I would recommend Winchester AAHS hulls. They can be used for clay target and hunting loads. With Winchester 209 primers, Winchester WAA28HS wads, a couple of sizes of lead shot and some Alliant 20/28 or Hodgdon Longshot powder, you'll be good to go. Or you could standardize with Remington hulls and components, or Federal... etc.
28 is an easy gauge to load because the majority of loads use the same 3/4 oz shot charge, so that also allows you to use the same wads in most cases. One type of powder will usually cover all the loading you'll likely do as well.
I start off shooting factory loads that use the hulls I plan to reload with. If you do any skeet or trap shooting, you can build up a supply of hulls quickly by buying and shooting, or by picking up hulls at the club, if it's allowed. You can also buy once-fired hull easily... check the classifieds here on the forums.