Many colleges like to see that their student applicants have been involved in community service and volunteer projects. Most colleges supply a form to explicitly list such student involvement. Sometimes it is hard to know here to find these outlets.
A first stopping place is your church congregation. We as Christians are commanded to reach out to others in Christ's love and can find many avenues in and outside of church to exhibit such love. Check with your pastor and fellow church members to find the outreach ministries recommended by it.
Below is a list of organizations and opportunities that some in our homeschool community have been involved with and have found beneficial and friendly to teenage homeschoolers looking for an outlet for community service and volunteer work.
(Note most of these are not Christian organizations nor have the primary purpose of evangelism.)
Beaverton Youth Peer Court: http://www.beavertonpolice.org/community/youth/peercourt.aspx
Clackamas County Volunteer Opportunities: http://www.co.clackamas.or.us/misc/volunteer.htm
Community Libraries always need people to help shelve books:
http://www.wilinet.wccls.lib.or.us/ (Washington County)
http://www.multcolib.org/teens/work.html (Multnomah County)
Guide Dogs for The Blind, http://www.guidedogs.com/site/PageServer?pagename=help_volunteer_puppy
Sightmasters Puppy Raisers, Washington County: http://www.sightmasters.org/
Habitat for Humanity: http://habitat.org
Loaves and Fishes, Meals on Wheels to Senior Citizens:http://www.loavesandfishesonline.org/ (This link appears to be having problems, please try the alternative link below for contact numbers and email addresses). http://www.mealcall.org/meals-on-wheels/or/portland.htm
Oregon Food Bank:
Pregnancy Resource Centers—call specific center for volunteer opportunities: http://prcofportland.com/
Providence Hospital: http://oregon.providence.org/patients/healthconditionscare/volunteering/Pages/default.aspx
Reading Literacy Program, SMART:http://getsmartoregon.org/ourmission/sites.html
St. Vincents Hospital: http://oregon.providence.org/patients/healthconditionscare/volunteering-at-st-vincent-medical-cente/Pages/default.aspx
Tryon State Park Youth Volunteers (from day camp counselors to grounds help): http://www.tryonfriends.org/individual-opportunities/206-opportunities-for-youth.html
Tualatin Hills Parks & Recreation: http://www.thprd.org/about/volunteer/home.cfm