I have DMed big groups in the past year and a half I've DMed, and I've found it's a hard path to tread sometimes. Here are some reflections:
1. Be firm about getting into the game. While D&D is a social game, and it's time to 'hang out' with a bunch of people you might not otherwise be with (which can be good or bad depending on where you're standing) things
can and
do get off track easily. You don't have to be "draconian" but encourage people to be in character, etc. Starting off with a "What Happened Last Session" has worked for me, and I need to get more into the habit of having that start-up. It gets the juices going for D&D, IMO.
2. Limit excess stuff. Music should be somehting appropriate for D&D - I've found that movie soundtracks or power metal works really well, but just other music gets off-topic ("I want to listen to X" "How about Z" "Wait a second, I have Y's album in my car --lemme go get it". If you play music at you games, the DM should also be in charge of switching CDs etc on top of that. And tell players to mute/turn off cell phones and ONLY take emergency/really important calls.
3. Food and drinks - while drinking is fine (hopfully non-alc; especially the DM
) and should probably be encouraged, food should not be lying around. I know it's a seterio type of gamers to have Cheetos and Mt. Dew, but honestly when you're munching down it REALLY does get distracting. And it's even easier with shorter games (like yours, Fool). If you have longer sessions like I do, when ordering/cooking food it's best to set aside an hour or so to eat and chit-chat (not in the gaming area, hopfully, since greasy fingers are the bane of gaming books) and relax - and then go back to it.
4. Late Players should have their PC played until they get there, and when they do arrive don't make a big fuss of it (hopefully they called ahead, however).
5. Absent players should be booted if it becomes a real problem. If they simply don't have the time to show up, you shouldn't have the time to ask if they wish to come.
6. Encourage PCs that mesh well together - don't have a party of Chaotic Dumbs running around doing random dumb crap, or a party of Neutral Evils running around killing people. Have "team players" and if one person continually makes a character which doesn't encourage this, have a talk with them - you may find it worth the while.
7. Definitly a good thing that you start off at level 1 - that way they can see their characters building up in power rather than trying to figure out how their wizard 1/fighter 6 +8 BAB came from, and what's their max skills ranks in Craft: Basketweaving are. If new players come in, my rule of thumb is the same with characters made after a PC dies - you come back one level lower than the parties highest level. IE, a party with 3 level 6s and one 7 gets in a fighter and one of the 6s die - his new character is rolled up as a level 6 character. Say the level 7 dies, he comes back as a level 6. Say a new player joins, well then her PC will be level 6. It's just easy bookkeeping, and it works okay.
8. Ruthlessly take out disruptive players. If they are people you care about, have a talk with them first to try to straighten thigns out. I have had to do this with a few players who were just jerks (One of my players continually got punched in the arm from this guy and I got a highlighter in my frickin' eye when the one guy tossed it to "check my reflex save" - too bad I was flat footed
). Also, you may have a few wallflowers in your group - those who are "just there". For them, encourage them as much as you can, but if they seem a lost cause, consider cutting them - it'll help streamline your groups size factor and free up more space for the players who are really into it to shine. With new players, this is really hard to see, you you might have to wait awhile to do this, Fool.
9. Try to squeeze in larger sessions. A nice side-product of this (if you can get it to work) if that if you can get in the good gamers into this longer session, you weed out the worse ones, which is win-win for you and the other players.
I think that's all I can say for my experiences with larger groups. I am now limiting myself to 6 Player/Characters and 1 DM (me) and haven't been accosted for a group larger than that yet. I've Dmed with 12ish players and it gets to be a bit much - thus I've had to cut a few corners. In the end, I ahve a good core group with both my two best friends and my gf in it, along with a changing number of players - there are quite a few on hiatus right now. In any case, I hope you can take a deep breathe and look over this advice a few times and work out somehting that works for you and yours. Oh, and welcome to EN World
P.S.
Once a Fool, I notice that your username also spells out an amusing acronym - O.A.F