Otherwise Known as Sheila the Great and Are You There God? It's Me, Margaret. were both childhood staples for me. But I loved all of her books, really.
Honestly, it's sort of an odd summer read, the story is fiction, but it takes place around the real life plane crashes in Elizabeth, New Jersey during the winter of 1951-1952. Judy Blume, who grew up there and was 12 at the time of the crashes. Regardless, I'd tell you to take it on vacation with you! I loved it and I'd recommend it to anyone who grew up on Judy Blume and all of her wonderful awkward characters who felt like friends in the "What? You too? I Thought I was the only one" sense of my C.S. Lewis quote from yesterday.
Also, for a truly summery Judy Blume read, check out Summer Sisters when you finish this one.