edited: freakout is over. Everything is fine. I actually looked at some of the forms in greater detail and figured them out. However, I did realize that doing my taxes online resulted in omitting some very significant data, which I will remember not to overlook this year. I might still want to learn a bit about this stuff though.
OK, today I received a letter from the IRS saying that I owe them $4000!!!! from last year's taxes.
I suspect I know why this happened, it has something to do with mutual funds. I am consulting with the guy who does my parents' taxes (they are both self-employed and own a house and can't deal with the huge hassle that is taxes) and it should come out OK.
However, this is really upsetting me because I realize that however much I WANT taxes to be transparent, and however much I would like finance and investment to be transparent, they are just not. It's not the kind of thing where, even if you're a relatively intelligent person who's good at math, you can look at the forms and realize intuitively what's going on. You have to learn some shit.
How do I do this? A "for dummies" book?