The date for GSL 2014 is set already. A forum post will go up with a link to a signing up sheet. Maximum of 4 people per team and maximum of 4 robots. There is a sign up fee, I think it was £25 per person last year. When I have signed up it has been either 4 weeks or 3 weeks before the event. My advice is build the machine and have it tested properly with 6 weeks to go before the event, that way you have plenty of time if something goes wrong.