Contact NASP, (National Archery in the Schools Program)
http://nasparchery.com/activea.asp?CompID=23&btnSubmit=ByFileID&cboFileID=6027&cboFileCategoryID=963They have grants available.
Also WSAA, might be of some help..
http://www.washingtonarchery.org/The TBW has WAJAM every year, where they (the kids) get to build bows, might be worth looking into..
I also remember somewhere where there was info on making kids bows out of PVC, cheap alternative to buying bows...
You might even approach local shops and ask for sponsorship...
Check out Junior Olympic Archery Development (JOAD) also, Ann Hoyt/Jim Easton JOAD Grant
The Ann Hoyt/Jim Easton JOAD Grant is made possible by archery legend, Ann Hoyt and current supporter of youth archery, Jim Easton. Through contributions from the Ann Hoyt Legacy Fund and the Easton Sports Development Foundaton, JOAD Clubs can request funds for items such as target butts, stands, archery equipment, general supplies and coaching certifications.