volunteers.aarp.org/ Register For Free & Find Ways To Volunteer In Your Neighborhood.
www.citgo.com/SocialResponsibility for Children, Youth & Adults. CITGO is Fueling Good in the Community.
www.positivepromotions.com/Volunteers Volunteer Thank-You Gifts Under $5. Shop Online at Positive Promotions!
www.oyemagazine.org/ Find volunteer opportunities, mission resources & more thru ¡OYE!
www.nationalbreastcancer.org/ Be a Breast Cancer Volunteer. Join The Cause Today.
How I did it: i first googled to find the organizations that like, and then contacted them offering to become a volunteer and attended my first meeting at one of them, and now i'm officially their volunteer, yay :D
Lessons & tips: just do it, don't wait around too much, just google the organization you want and contact them right away, no need to be shy, go for it!
Resources: the internets, google