Okay, I have no experience as a dm and very limited experience as a player, but everyone's gotta start somewhere. I've been thinking the play-by-post forum here looked like a good idea, given my difficult to predict schedule, but I've only really got the basic rule books and I'm not sure exactly where to begin. Would anyone mind sharing a little advice to get the ball rolling? I'm kind of nervous about joining or creating a group unprepared.

I'm not sure the play-by-post is the best choice for a new DM, as it has its own idiosyncrasies.  But it's not an impossible choice.  I would encourage you to be upfront about your experience level if you do offer a game.  I would recommend you start by running the Lost Mines of Phandelver from the starter kit.  Or, if you live in the US and have access to a Target, you could pick up the new Essentials kit, which is expected to be good.  It officially goes on sale exclusively at Target on Monday the 24th, although I've heard it's already on shelves in some Targets.  It won't be available outside of Target until early September.  The Essentials kit includes a code to get the adventure here.

A couple of other tidbits of advice:

-When I started, I gave myself permission to ignore/not use several of the rules because I felt overwhelmed.  Those included: encumbrance, reactions, and opportunity attacks.  Once I felt more comfortable, I added most of the rules back in, although I still ignore encumbrance issues.

-In the midst of play, be willing to say "This is how I'm ruling for now; I'll check the rules out of game, and I/we may decided to handle it differently later."  

-Don't get too invested in a particular outcome or plot direction; players have a tendency to go in directions neither we (nor the published campaigns) expect.  

If you decide to start a play by post game here and don't find enough takers, shoot me a message through the system here. As long as the tone of the game is one I'm o.k. with, I would be willing to join to help you out.