Having your DNA tested with Family Tree DNA would be a good place to start. You may have already done this.
Once you have your results, you'll be able to look over the matches they provide. Sensing out email to them asking about there family tree, family stories, family locations and where their family origin might be. Ancestry.com may be able to help with finding a paper trail or other people who have posted a family tree. Then you can send them an email asking questions as I had mentioned earlier. If you have your DNA results from Family Tree DNA, then you might want to visit www.grdmatch.com. They offer more connections and tools you can use. Again, you can send out emails. Once you start establishing connections and exchanging information, you will start building up your leads.