theantijock saidRead any of the big boys. William James or Carl Jung are among my favorite thinkers.
Or you could get into it through some fiction which might not be necessarily instructive but certainly illustrative of principals of psychology, the real heady stuff like the works of Henry James, Borges, Marquez, et al.
But aren't James and Jung a bit outdated already?
Well, yeah, but so's Confucius and Laozi.
Thinkers who transcended their generations generally also transcend ours.
Is there new info, has some stuff been tweaked? Well in some cases, maybe so. But you'll rarely get better information than by going to the source.
Also, reading them will show you not so much what to think, but how thinking is done.
Otherwise what you're getting is translations (and when you work with those, find someone reputable who doesn't just understand the language but also the topic, how the language should be applied) and interpretations (most of which are prejudiced crap) and colorings (so unavoidable) and embellishments, etc.
So go back as far as you can into the thinking of the thing and then contemporize it yourself so that when you read the more current stuff, you'll be better able to pick out the bullshit even where some of the information might be quite good. Especially because so much of what's out there today is written to sell, not to enlighten.
Either that or maybe you could check out what books some early psych college level class is using so you get the real stuff, not the for sale stuff.