The best successful example that I've seen of what you're describing is the Woods Hole Film Festival in Cape Cod, MA (although by the time I went there it had been around for 20 years so I'm sure they had plenty of growing pains).
They did not have famous people, but they did have filmmaker breakfasts and other events/parties that were great for networking. I'm still in touch with a number of filmmakers that I met there.
I second this. I've attended Woods Hole several times. As and actor, as a filmmaker and a few times as just an audience member.
In fact, I met Mara Leseman and her director Laura Thies there at a filmmaker brunch!
Another thing I will point out about Woods Hole - They make your film look pretty darned good. I have had my films screen in all the different venues and they looked and sounded superb. I actually can't say that about a lot of festivals I have been to, including some pretty well-known ones.
With regard to your festival, you mention you are in a tourist town. An important question: Is this an expensive tourist town? The reason I ask is that a filmmaker will need to take into account the cost of coming and staying at the festival. Since you are so new, I am assuming you won't be able to afford housing the filmmakers. This is something to keep in mind. I really like festivals who send out very detailed tips and suggestions about where to stay, discounts, etc.
Communication is key. There are some festivals that send an email that says, "Congratulations, you have been selected." But then, they literally never send you another communication without you bugging them for more information.
Keep sending out regular updates to your selected filmmakers. Let them know exactly what to expect when they get there. Who do they check in with and where? If they have any problems who do they contact? How many comps do they get to their screening? What does their Filmmaker badge entitle them to as far as special events and screenings? Do you want them to be on a panel?
Let them know all these things way in advance.
Lastly, the best thing to ensure your success is to cultivate a great volunteer squad. This is the most important thing you can do. Even the larger premiere festivals I've attended - IFFBoston, Sundance, Tribeca, Nantucket etc. rely on an army of volunteers.
Make it fun and worth their while. Many festivals, especially in their early stages, give volunteers free access to the films if they complete a certain number of volunteer hours. The way IFFBoston works: If you do two volunteer shift of 5 or so hours each,you can then attend any movie at the festival for free. Volunteers show up at least one hour before the scheduled time of the film they want to see. If there are tickets still available, they are given a ticket. If the screening is sold out, they have to wait in the standby line, but they are the first to get tickets if there are standby tickets available. Volunteers are also given access to certain parties and special events.
One more note: And this is just a pet peeve of mine, please, others chime in if you have had the same experience.
Nothing gets me off on a grumpier note with a festival than arriving there and looking around the main box office area or the venue areas and not seeing posters or postcards placed around the area for any films after you had us filmmakers spend shipping costs to get those materials to you a month before the festival started.