Cool! I finally contributed some money to his campaign just a few days ago, and would love to volunteer, as well, but presently have no time.
Re financial contributions, every dollar counts, folks. Note as well that everything that you contribute will likely be matched by the federal government in Dean's campaign, so your contribution will go much farther than it otherwise might. Even five bucks helps.
Edited to add: shortly after I wrote this, I saw an article saying that Dean may in fact forgo federal matching funds. Still, any contribution helps!