Seriously though, if I'm going 3.5 what module should I start them out with?
...opinions will vary. Mine is: don't have your first DMing experience be with an official module. It's certainly a valid choice, but you're going to have enough to deal with without juggling a module, constantly hunting for the flavor text to read, trying to keep the players on task, dealing with it when they don't, etc. all while
teaching your players how to play the game. Formal modules have too much overhead. I'd advise a simpler experience for your first session.
First session, figure you're going to end up spending 4-5 hours just helping people make characters. You might not even get around to actually playing. If you do, it should be a relatively stripped down simple combat encounter to familiarize people with the combat mechanics, which dice to roll, how far they're allowed to move on the map, what their combat choices are, etc. Even if you make characters with everyone separately and go into the first night with characters already made, still expect to spend a
lot of time teaching people mechanics. Don't expect to have an epic role playing experience or a huge, well thought out plot arc.
Instead, just come up with a fairly simple scenario that will give you an excuse to have some combat, and maybe explore a small cave. Maybe...traveling between towns and ambushed by kobolds on the road, with the kobold lair visible from the road. Or the players can be traveling through the woods and stumbles onto a cave, or find a crumbling hole in the ground leading to a cave...caves are good. Spend 2 minutes drawing up a simple cave map with at most 3-4 hollowed out rooms connected by short tunnels. No need to have a full-on, complex dungeon with traps and pre-set encounters. On your first night, 3-4 rooms in a cave will be plenty to keep you occupied.
A few mechanics suggestions:
* In combat, don't bother with initiative. Simply take turns. Simply rotate clockwise around the table through all the players, then you as the DM handle monsters. Repeat. Big time saver, greatly simplifies things and nothing is really lost.
* Assuming you're using a map, I suggest allowing players to move their own pieces. However, expect to have to watch them for a while to teach them how far they're allowed to move per turn, and maybe a little longer before they'll be honest about it.
* If they don't have miniatures for themselves, coins, bottlecaps, monopoly pieces or anything else will work fine just so long as everyone knows which one is theirs. Again, use dice for monsters and set each die to show face up what each monster's number is. It is a
major hassle to have half a dozen orc minatures and try to figure out who is attacking which and which miniature corresponds to which label on your notes.
* For monsters tracking, get a simple pad of paper you can tear sheets off of. At the top write generic monster stats, then simply give each monster their own line and just write something like this:
1) 12
2) 8
3) 8
4) 8
What that means is that you have four monsters. The first one has 12 hit points, and the next 3 have 8. When they take damage just scratch the number out and write their new total. Players can move their own miniature, tell you which monster they're attacking, roll, and you can quickly and easily scratch off hit points without having to go to the map yourself. Once your players are well trained you won't even need to
look at the map except during the monsters' turns.
Again, just one possible opinion...the people above arguing over min/maxing and "which version is better" and so forth are giving you a very misleading view of what the experience is actually going to be like, and what you actually need to know. Whether TSR, WoTC, Iron Crown or whomever made your ruleset really doesn't matter at the end of the day. All the above silliness about overpowered classes is complete nonsense. Any competent DM will nip that in the bud right away and it will never be a problem.
What you need to do is not worry about versions or rules so much as
becoming a competent dungeon master so that you'll know how and when to deal with things. That will take practice. And probably some trial and error. And it doesn't start by arguing over versions or classes. It comes from simple stuff like the above. Conducting your games in such a way as to engender a smooth and enjoyable gaming experience for everyone.