My benefit shows have been for the Safehouse/domestic violence project, and Ann Arbor hospital. You should choose something that's important to you, or that is local. Local is key. If you get a local charity and some local talent, you'll have a better chance of filling a room. Craig makes a great point, I usually have all of my advertising in 1-2 months before the gig. Most papers have a weekend section where you can list your event for free. Hit all of them. You can probably find the contact info on line. THere is probably a monthly entertainment local you can get into for free as well. These are great contacts to have for benefits, your own shows, etc.

Find a couple of local bands with a little buzz, and check out their shows. Tell them what your putting together, and just ask them to play. (ask at least a month in advance) Once you secure one band with a little buzz, the rest will be happy to share a bill with them.

George is right about the number of acts/time limit thing. Just take the length of the gig and the number of acts and divide.

The other thing you'll need to consider is sound. We had 23 acts last year, and our sound guy deserved a medal of honor. If you get more that 2-3 acts, you may want to have a house drum kit, amps, mics, etc. to save time on setup in between shows.

let me know how it comes along.

-spartacus