I was elected President of our LUG before my Sophomore year. It was already somewhat established but that doesn't change the fact that I had no idea what I was doing, I just happened to be the biggest zealot at the time. You have to go find people who do know what they are doing, and who have ideas. Then you have to filter out the bad ideas, which is an exercise I continuously failed at and will leave to the student. Also remember you're starting a university club, which means you can not count on anyone for anything. If someone promises to be somewhere, just assume that it's not going to happen and be pleasantly surprised if it does. But if you find a couple few people that you CAN actually count on - they are your inner circle and should probably be officers.
I'm sure you're looking in your Engineering department for faculty and students that are interested. But some of my most interesting experiences came from outside the CS school. We had a Philosophy and Religion professor that would come by meetings from time to time and basically was an old hippie who got into computing early, and just preferred command line interfaces for checking email and did all of his publishing using LaTeX. Several University Staff were interested and regularly helped out. (Go over to the IT department and ask around - this is the most likely source of people that have been involved in LUGs before.)
Also look for interested students outside your Engineering school. There are lots of different reasons to like Linux and Free Software, very few of which require the math education that Engineering requires. You will find the best zealots in the most surprising places. One of our members that stands out in my mind graduated with a degree in Broadcasting, but due in part to his time in the LUG was hired on at Red Hat for tech support and has moved up quite a bit in the company.
If you can find a passionate Business school student who also enjoys Linux, this person is your best friend. Let them deal with organization and getting people together and such while you focus on technical aspects.
Beyond that just get the word out there and have interesting events. Make sure you have meetings at regular intervals, not so often that people get sick of it and not so rarely that people think it's defunct. Once a month is probably a good bet, and at that meeting you can announce other events happening during the month. Installfests and LANs are always fun. Keep in mind that if you hold a LAN party and successfully get the word out there, you will end up with Windows PC Gamers all over the place, and not a few consoles as well. It's not a bad thing - think about it like raising awareness. The regular meetings should be accompanied by some kind of presentation. Get your VIM expert to talk about cool VIM stuff like good ideas for your
I guess if I have one point to make it's just that you shouldn't let your perceptions limit who all might be interested in this club. You're probably not going to fill your meeting space with sorority girls that are really interested in Free Software, but don't assume that they're all completely disinterested.
Oh yeah. On the topic of girls at a LUG meeting, be alert and aware. There tends to be a "boys' club" mentality that will scare the ladies right off. Just make sure that the meetings are welcoming of everyone and if you have some male members that are being creepy or causing a problem, discreetly nip it in the bud when you notice it and have a private chat with them later. It's possible to have a relatively diverse LUG if you do it right.