MrkLin said it all very well! Read what he stated very carefully.
We entered the lifestyle with MFM, with my husband's best friend of almost 20 years. He does not live anywhere close to us, was in town to visit, and he and his wife have been swingers for a few years. So while he was a "vanilla" friend to us, he was at least somewhat into the lifestyle. It was a great way to start! No regrets, still close friends. But then again, we haven't seen each other in person since.
Our 2nd MFM was with a close friend of both of ours that does live closeby, and he had been involved with MFM years ago with an ex-girlfriend. However, I will honestly say that it has strained our friendships. Jealousy from Mr. NC, as well as awkardness between the 3 of us, we haven't played in a month after 2 tries. He is very close to our children, who call them "uncle", and spends a lot of time with us as a family. We are trying very hard, all 3, to restore the friendship back to what it was.
Long story short - I think anyone that you meet in the vanilla world should stay that way. While it may seem more comfortable to start with someone you or she already know and are comfortable with, you cannot predict how everyone will feel about it the next day, a week later, or a month later. Try a local club - do they have nights that single men are admitted? Ours does on Friday nights. Create a profile on other search sites - there are plenty of single man that are already involved in the lifestyle that better understand a couple wanting to share this experience.
And as you've read above, you will have to wade through the profiles. We recently received an email from a single man - "Got 10" hard for u baby" - my response? "Is that really your pickup line? Good luck". Do not get discouraged - she will know who interests her and who doesn't, and together you meet them and decide whether or not to take it to the next level.
Out of curiousity - why is it that you want to start with a single man instead of looking for couples to share the experience together with?