I've been involved with lego league for the past three years, and I would definitely recommend it! Here's my advice for running a lego league team:
1. Make tackle boxes for your lego kits! Fishing tackle boxes work well. label the compartment to show which pieces belong where (a picture of the piece along with the number of that type of piece printed below works well). This way, when the kids are cleaning up they know how many pieces are missing. If you don't do this, plan on loosing about half of the legos during the project.
2. For a team of 8-10 elementary school students, 3 mentors (high school students or adults) is about the minimum. Try to have the same mentors each week, so they can form relationships with the students.
3. Plan on meeting twice a week for 2 hours in the beginning, with some extra work time thrown in the last few weeks if things aren't coming together well.
4. It's nice if there is a 5-10 minute snack brake halfway through the meetings- the kids complain about being hungry if there isn't, and it makes them more focused when they come back. This is a good place for parents to get involved- assign each family a week to bring a snack.
5. Have fun! Remember that it's their robot, so try your hardest to keep from building it for them

. If the kids don't have an extensive lego background, the "constructopedia" (which comes in the mindstorm kit) is a good place to start- it has explicit directions showing how to make some simple robots.
If you have any questions, feel free to email me at
cconley@gunnrobotics.org . Good luck!
-Caroline Conley
Gunn Robotics, team 192