A couple more suggestions, if anyone's still looking--
The Common Ground Country Fair is a HUGE festival in central Maine, that attracts people from all over the state and beyond. It's an agricultural fair, but there's no rides or fried dough or anything-- just tons of arts & crafts, concerts, and organic food vendors, plus the more typical farm animals and demos. It has a great vibe-- lots of artsy people attend and exhibit, and people sell everything from high-end, precious stone jewelry and artisan furniture, to recycled metal sculptures, aromatherapy candles and soaps, and homemade jam. It focuses on things made/grown/baked in Maine, but it definitely has more craftster-type edge to it than your average country fair. You have to apply to be a vendor, and the more handmade your stuff is, the more likely you are to get in. I think there may be stiff competition and an exhibition fee, but it's worth it for the ridiculously huge crowds that attend every year, rain or shine! I've never exhibited, but have volunteered there for years, and it's always a really fun event. www.mofga.org
for more info - just noticed the vendor DEADLINE IS JANUARY 28th, if anyone's interested!
Also, Ogunquit has a Sidewalk Art Show in the summer-- it's only one day, but there's always a good crowd(with locals and tourists), and there's a nice mix of all kinds of artists (photography, woodwork, sculpture, etc). According to the chamber of commerce website, it's going to be on August 24 this year. http://www.ogunquit.org/calendar/Web_Event_Display.cfm?eventID=823
for more info
It's so hard to find out about fairs when you're just starting out (like me!)-- anyone have other suggestions?