I'd like to invite you and your wife to read my incredibly long blog post titled
How We Got Involved in Swinging <~That's the link.
It's a long post (4 pages) but it may answer a lot of questions for both of you. Our first swinging adventures were MFM threesomes, so I know where you're coming from. Check it out and if you have any questions at all, feel free to post them here or PM me if you'd rather.