To understand their character and expertise, there are many opportunities to sample the goods.
Associations / Memberships
What others say (social proof)
---- Watching a leader in a group in action over time will reveal character, expertise, style and intent.
It is not always a matter of "good" as much as whether there is a synchronous communication. Intention is more difficult to weed out.
Buy someone lunch once a week. Dining over an outstanding meal opens people up. :)
Sometimes the best advisor is someone 10 steps directly in front of you. They can point and let you know - "watch yourself".
Finding good advisors is not as difficult as getting them to care enough to invest time and effort. Which means "the mission" should draw them in.
Which brings us to Guy Kawasaki - Make Meaning in Your Company
Watch the video:
Once you find them, then --- how will you inspire and motivate them to care enough to participate? (Then I focus on what they are interested in, their mission, and is my mission aligned with theirs?)