I hope you have looked at the stickies on top of this forum, included are book recommendations and other threads worth reading. I would suggest for sure reading if you are going to try this is "Opening Up" by Tristan Taormino. It starts a bit out there if you aren't a kinky person, but it has a lot of good checklists and questions to go over with each other, which I think is great for people who are going from mono to poly. Really though I'm a "read as much as possible about the subject" person, so I've read most of the books I can find and they have ALL had some value, and something worth discussing in them.
To tell your parents? Well lots of people wait until they are dating somebody seriously before telling parents or friends or coworkers about it. Some people never do if it's not going to do anything but worry them. Maybe you try this for 6 months and it doesn't work out - would you wish you had kept your mouth shut or that they knew? My mom's a swinger, my dad's an ex swinger and rampant cheater, therefore I didn't have any problem telling them, so my advice isn't much use I'm afraid. Really the worst was my Mom trying to tell me I was making a mistake and I should swing because it was "safer" for the marriage then sleeping with somebody without my husband there
There are a number of threads on here about coming out and telling people if you do end up wanting to share it though.