Um, those two things are not related by the way. There's no self-hate involved in loving Allie Brosh. She's amazing. I just wanted to cover the two audiences I'm hoping to reach here.
SAOP is a collection of stories about her life, presented primarily as comics with explanatory text between sections. If you haven't read her stuff, go to hyperboleandahalf.blogspot.com and see if you like it. Basically, Brosh's talent is in using simple, expressive art to make her stories incredibly accessible and relatable. Even if you didn't do the same stupid stuff as her, you totally get it and can't help laughing.
Usually laughing, at least. Brosh has always talked (and drawn) about her depression and other mental issues, too. And SAOP goes harder there, because she had some bad times since the last book. Some stories end up being a (very natural) mix of heartbreaking and heartwarming, still incredibly relatable even if I didn't go through quite what she did.
Stories range from her childhood, where she almost got an innocent man painted as a child predator (and yet it's an adorable comic), to growing up with a wide range of stupid and neurotic animals, to coping with life after her marriage fell apart.
The most interesting chapter for me was the last, "Friend." It's presented as a guide for "How to Become Friends with Yourself," based on her own attempt to overcome loneliness and self-loathing. That's the sort of advice you'd expect from a self-help book with some smarmy pop-psychoanalyst on the cover. Useless, coming from the perspective of someone who already has their shit together and is trying to raise you up to their level.
But this isn't that. This is written by someone who understands what it's like to hate yourself. It's her take on how to gradually, painfully learn to accept a person who you can't even stand. A stupid loser you feel stuck with, but decide "screw it, let's at least TRY to get along." I found it incredibly relatable and helpful, and if you hate yourself, maybe you will too.
Anyway, whether that^ is you or not, the whole book is incredibly worth reading. I'm glad Allie Brosh is "back."