I do not have much in the way of reference info on the PIC at the moment but I do have some good links. I only present the best links so you do not have to waste too much time.
This is a good site for newcomers to the PIC.
There is a mailing list you can join, beware of the high traffic though. A lot of professionaldevelopers of the PIC are on this mailing, as well as a number of hobbyists, a great reource for PIC queries.
There is a FAQ, read before posting to the list.
The manufacturers of the PIC microcontroller. They have application notes, PC development tools and a whole lot more on their site. They encourage the hobbyist user, which has helped the PIC become number 2 in the 8 bit microcontroller market.
Updated 27 September 2020