Oh, and about who the president will be - at some schools, the bylaws allow the principal to appoint officers if none can be found through nominations and elections. I would guess that since you're willing to do all the work to form the group, you'd be an awesome president.
Remember to take some personal time to rest. It's easy to get overwhelmed by a project like this. And keep your positive attitude - it's contagious!
In addition to the great suggestions above, I'd suggest contacting PTO presidents at neighboring schools. They probably would be willing to give you helpful local information as well as a copy of their bylaws.
Our biggest fundraiser of each year is a frozen cookie dough sale with Classic Cookie. There is no cost to start because the company provides all the materials for the sale. They even provided sample cookies for Open House last month. You send the packet home with each student, and keep 50% of each sale. The cookie company pre-sorts each order by student for delivery, and you still have time to do one before holiday baking begins. I would suggest a telephone committee to remind parents (a couple of days ahead of time) of the date and time to pick up their orders.
At one school where parent involvement was abysmal, we scheduled things like Popcorn Ball Night and Christmas Ornament Night - cheap, hands-on events to get parents and their kids to come out. Once there, we held short (10 - 15 minute) meetings just to let folks know what we were up to and to encourage participation. It was slow going, but eventually there was much improvement.
In regards to a good starting fundraiser, I would suggest one of the types that could go home before the holidays and could allow the parents an opportunity to purchase a present for someone. We use Yankee Candle and I feel it is one of the easiest and more profitable fundraisers. 40% profit and the orders all come in boxed with the person's name who ordered, as well as the teacher's name, to make it easier to separate and disperse.
For a school of about 500 we usually bring in about $9000.
Many schools use the magazine subscriptions, or things like that.
One thing that I would recommend staying away from would be the ones where the kids would need to go door to door. Buying from family and friends should be enough.
Other than that you might want to look into local company programs. For example, we run three roller-skating nights throughout the year and usually profit about $1000 total, we also use Friendly's and Papa Gino's, where we get a certain % of ALL sales for a certain evening.
The IRS has a good summary of the life cycle of a public charity. This goes through the formal steps of organizing. Be sure to look at the graphical depiction also.
