Best Advice I can give from experience is to help out the new guys with the learning curve. We can all agree that FIRST has a HUGE learning curve and there are many people that have to be helped along with getting into it or else your team won't grow. Also, when people aren't doing anything, either get them doing something or have them sit over the shoulder of someone who is doing something that they don't yet know how to do so that they can watch / ask questions, and as a result, learn how to do it so that the next time they are asked, they can do that job. Keep everyone interested and getting better above all else.
And congratulations on the position!
