Getting started on first in ground pool

Just found this forum. Thank goodness as my wife and I are trying to make decision on new in ground pool. Is there a sticky or guide I should be looking at instead of posting a thread like this looking to cover all the questions I have. Concrete? Fiberglass? Vinyl? How big a pool vs bigger deck/entertaining area? Our yard is large and budget is likely $50K. I came into this thinking I wanted a 36-40' lagoon or kidney shaped salt water pool that has a deep end and diving board. I'd trade some size or even the diving end if needed to budget for great area to entertain with our friends. Is there a guide I should follow somewhere? Am I in the ball park budget wise. If you knew then what you know now what would you do in my shoes!
I have 3 sons 11,13,15 and our friends all have kids that will likely log a lot of time at our place.

Looking forward to all the educated help!