Since you are female, you can contribute by taking an mtDNAPlus test at www.familytreedna.com (FTDNA) (only about $59 plus $6 postage) or a "mtDNAPlus + Family Finder" test (for an additional $99) at FTDNA.
Males can contribute by taking a Y-DNA37 (or through a project - Y-DNA25) test at FTDNA. Males can also take an mtDNAPlus test and a Family Finder test.