The INNOVATE 2013 game jam will begin Monday, Jan 21 for the Pro track participants and Friday, Jan 25 for the Hardcore track participants. The schedule is above. Everyone will finish Sunday, Jan 27th at 5pm ET. Plan to make your game available for everyone to play by the following Tuesday. The Williams Graphics Lab will be open 1-4pm to showcase the games as well.
The time limits of a jam are intended to keep it fun, light, and creative; without them it might devolve into yet another project for a group of already hard-working people. Everyone is welcome to work on their design or do little prototypes beforehand and to polish afterward, but I recommend really following the spirit of the time limits and not overloading yourself.
A recent article by Christer Kaitila has some advice on your first jam, based on his Ludum Dare exit survey: http://gamedev.tutsplus.com/articles/business-articles/how-to-get-the-most-out-of-a-game-jam/