Team 25 holds a summer lego camp, as well. About 3-4 years ago, a group of students came up with a curriculum, which is the basis of our current one. The first few days are spent teaching the basics: drive trains, gear ratios, and some basic programming of sensors.
During the 3 weeks of the camp, we have challenges that the kids are given 1-2 days to complete, such as hitting a ball into a net, throwing balls, "sumo wrestling," and robot bowling. At the end of the three weeks, we allow them about 2-3 days to build a robot to complete an obstacle course that combines many of the objectives from previous challenges. The tasks were easy enough for the kids to complete, though some assistance from the robotics team members was required.
This year, we had 4-5 students from the team volunteer at it, 2 parent mentors with about 10 kids. We tried to divide the kids up evenly into groups of 2 or 3, since we had a limited amount of Mindstorms kits. Our camp was held at the parish hall of a local church for no fee, which worked out really well.
We charged $70/student for the entire three weeks. This seemed to really help with the success of the camp. Many parents came up to us and told us that one of the reasons they chose our camp was because of the expensive prices of other camps (for example, Middlesex County College offered a camp that cost $800 for only one week longer than ours). However, we're thinking of a possible increase in the cost to help pay for some possible new NXT kits.
If you hold the camp, definitely make sure you hang signs up for it everywhere: pizza parlors, shopping centers, etc. We kept our registration open until the day before the camp, which seemed to work nicely. Try getting yourselves organized in early to mid spring so you can have the signs up for a good 2-3 months before the camp.