said 8 months, 3 weeks ago:
Finding them – You can use Klout’s search feature, enter in the specific topic and find influencers. If they have a Klout profile they usually have their Twitter/Facebook info. One of my favorite tools is Followerwonk.com. I’m not sure exactly how to describe it (other than marketer’s candy). It has Twitter info but you can find influencers and just look them up on Facebook. You can also just search Facebook groups but if you want more details about the person, use Klout or Followerwonk.
Engaging them – Just ask. It’s remarkable the things people will do to help others. You can mention their name, send them an invite to join your page, etc.
Keep them interested – Look at what type of posts they already engage with, links they share, etc. If you post content they already engage with, it’s likely they stick around.