Just wondering if we are allowed to do any kind of prep-work before the jam starts, since it doesn't start for almost a month. Could we start making the game before the jam, or does it have to be created in the span of the jam itself?

Also, are we allowed to submit multiple entries if we so desire?

The intention is that creation of the games happens solely during October, but I have no way of checking and I don't really mind what you do. 

WRT to multiple entries, I don't see why not.