[Mr. 16 gauge]

What you described doing is basically how I went about doing it.....I didn't know anyone who turkey hunted, so I got some books, video tapes, and calling tapes and read & listened. Box calls, as noted, are the easiest to learn on, and you only need to learn a couple of calls to get started. Also, I would suggest patterning your gun with your full & modified chokes prior to buying a turkey choke....I found that my full choke in my 870 express was plenty tight enough for turkey hunting.
One thing I haven't seen mentioned here is scouting.....get out in the woods pre season and look for birds & signs of birds BEFORE the season starts; that way you will know where they are when the season opens. Look for tracks, feathers, dusting sites, dropppings, ect. The books & tapes should give you more info, but that is the basic gist of it.
As for patterning, I would suggest trying 3 or 4 different turkey loads......I like #5 shot, but anything from #4s to #6s work well for most folks. Look for buffered loads with nickle or copper plated shot....both will help to tighten patterns. Finally, I like to use where the neck joins the body as an aiming point....if you are a little off, the load will still be lethal, and if recoil is severe or you are off balance, you will still put enough pellets in the head and neck to be lethal.
Good luck..................