I think it would behoove you both to move slowly, and to discuss exactly what you'd be comfortable with. I keep reading time and time again on these boards that things should go as slowly as the least comfortable person needs it to be. So, in my opinion, it might not be best for you guys to start off with your wife having overnights or weekends away -- you don't even need to think that far in advance! See how you feel when she goes out with someone on a coffee date, or when she kisses someone else. Let those feelings sink in and then share them with her, or find a way to deal with them. You likely would benefit from having some agreement in place on how far things can go before moving to the next step. And yes, browse through these forums, especially in the New to Polyamory section - a wealth of information!
The world opens up... when you do.
Oh, oh, can't you see? Love is the drug for me. ~Bryan Ferry
"Love is that condition in which another person's happiness is essential to your own." ~Robert Heinlein