At the risk of being hailed jerk, I'll direct you to the search feature here on this site. Not because I don't want to talk about it with you, but rather because it's been talked about quite extensively already, and a search will yield you tons of good information.
My PPE selection is varied based on what and where I'm cutting. Different helmets for falling, climbing and firewood, etc. Provided the search function is working, you'll read some of my posts elaborating.
Welcome to AS.
Jeff