Anna, as someone mentioned previously, do some project planning and try to stick with it during the build season. Six weeks can slip by so fast... MOEmentum breaks it down by week so you have an idea what needs to be done by when.
http://www.fsrobotics.org/moe365//moementum.php Team-in-a-Box is another great resource, as is RINOS. They are all linked from the NEMO website at
www.firstnemo.org/resources.htm