If you guys are in love - and have a great relationship then go for it. You might start small - but in the experience of my wife and I - a foursome (another couple) is both easier and more comfortable to start with than a ********* (which are GREAT too). But make sure neither of you is doing something you're uncomfortable with, have safe words and a way out if something feels wrong.
To find someone or couples - try some of the swinger sights like swinglifestyle or better yet kasidie. You can join for free, and it does still work, decide if you like before upgrading.
Best of luck, have fun!
Our first "date" was with a couple we found on a site. Although we have gone to a local club a few times - and that is also a great way to look around, talk to ppl, and see if you want to go somewhere for more (off-prem club) - even if you don't, the two of you can leave there sexually charged for eachother.
I'd start small and work your way up. For example, have a ********* first, then another couple and so on. It's the best way to make sure you're both fully into it and okay with it.