As many teams starting in imagine cup, there will be also huge numbers of newbe at programming, and I would like to give informations that will be helpful to them.
First, you have to manage your team and tasks, I use trello because it have pith of GTD. Just do it don’t use complicated system, it is not needed.
Second, you have to keep somewhere files of your projects (not only sources) and with help comes bitbucket, there is also github but unfortunately private repo is paid.
The least but not least, when you need sketch something or plan it use these few tools Microsoft Visio. I think it’s the best tool to create model of database, what else ? if there’s need of simple mockup of website or application I recomend you Moqups.
P.S Well, code, code and maybe we will see at St. Petersburg 😉