We don't have any books on colossal squids (scientific name: Mesonychoteuthis hamiltoni), but we do have several on giant squids!
Ellis, Richard. The Search for the Giant Squid. [594 ELL]
Sherry, Kevin. I'm the Biggest Thing in the Ocean. [JP SHE]
We also have an adult novel dealing with a squid, and, it was very well-reviewed! The Highest Tide [F LYN] by Jim Lynch. Here's the publishers description:
One moonlit night, thirteen-year-old Miles O'Malley sneaks out of his house and goes exploring on the tidal flats of Puget Sound. When he discovers a rare giant squid, he instantly becomes a local phenomenon shadowed by people curious as to whether this speed-reading, Rachel Carson obsessed teenager is just an observant boy or an unlikely prophet. But Miles is really just a kid on the verge of growing up, infatuated with the girl next door, worried that his bickering parents will divorce, and fearful that everything, even the bay he loves, is shifting away from him. As the sea continues to offer up discoveries from its mysterious depths, Miles struggles to deal with the difficulties that attend the equally mysterious process of growing up.
(For those of you in book clubs, this might be a great title for discussion.)
Okay, who's up for a little fried calamari?