Depends how they wish to learn, but I like to start most people off with Michael Parenti. Most people are easier to get with pamphlets or videos, but if they want books then I like Blackshirts and reds though that’s mainly because I think it does a good job of deprogramming anti-communist propaganda
edit: @Cowbee@hexbear.net and @MohammedTheCommunistPalestinian@hexbear.net have both made fantastic lists. I’d go with their recommendations