I second serching around for a class. In particular, look for a First Steps course. A bit of professional instruction will be invaluable. An instructor will assume you know little and as such won't leave out things under the assumption you know. Instructors also know all the questions relative noobs have. Best of all, they know how to spot bad habits and how to correct them.
I took a first steps with my wife and learned several things I diddn't know, even after going through rifle training in the army, reading countless gun mags, and shooting for over a decade. The course covered everything from basic marksmanship and safety to different action types and legal considerations. In addition, we ran the concealed carry course of fire for fun with a .38 revolver and Glock and then wrapped it up with firing several other handguns for fun.
Another personal experience with training. After shooting for quite some time, I invested in a little bit of private training. In 30 minutes, my groups shrunk in half. Turns out I had a couple of bad habits that I never realized. The instructor said "Hey, you're doing X, try to focus on not doing that." Voila! After years of shooting with others, many of them long time shooters, no one had ever pointed them out to me.
I took my course through the local junior college. I've also seen them offered by private instructors, ranges, and gun clubs.
Once you get to the point where you can comfortably and safely operate firearms on your own, find a range that rents and try out whatever strikes your fancy (though I might avoid the temptation to take the big magnums for a test drive).
Finding a few buddies that own a lot and are willing to take you out (and it sounds like you already have a few) if you pitch in for the ammo and perhaps do some cleaning or buy a couple of beers afterwards is a great way to get acquainted, too.
One last bit of advice, if you're even remotely interested in rifles, attend an appleseed (
www.appleseedinfo.org).