Sheri,
I too am in charge of a fundraiser every year. Me and my mom are the two main ones in charge. We find that a lot of people ask us what they can do to help and we always tell them to go out there and find 2 people to come. This has helped us a lot. Also, I did do some research on why people attend fundraisers and realized some interesting things...the people attending do not necessarily care where the money is going. What they know is that they are doing their part in helping raise money for 'something' and feel that they have fullfilled that duty for the year. What the attendees want to know about your fundraiser is 'what is in it for them?' So this is what you will want to stress (ie. what prizes do you have in the raffle).
When I sent out the invite this year, people didn't really pay attention to the fact that they would 'be helping 30,000 families in Illinois that have MS' but they sure payed attention to (and commented on) that fact that there were going to be 3 flat panel TV's in the raffle again.
That is about all I have. I learn more every year. But I agree that selling the tickets is the hardest part.
Good luck with your fundraiser.
C.