I've just finished Harry Potter and the Order of the Phoenix, and with one running story thread in particular I can identify closely: studying your ass off.

On Tuesday, I loaned from the library Tropical Fish: Every Important Group of Freshwater Fishes Covered by Neal Pronek. Fishes? Mmm-kay. It's a great book full of strong opinions and clear guidance. It's 64 pages long, filled with gorgeous photography. I read it in less than an hour, craving more.

Over the last couple of days, while on a mini-vacation at Wilbur Hot Springs, 120 miles north of San Francisco, I pored over two fascinating books, one of them -- seminal -- co-authored by Mr. Pronek. Aquarium Fishes of the World, at over 1,000 pages, is biblical in scope, the type of full-color reference book reference-book geeks like me gobble up.

The other book, Aquarium Owner's Guide: The Complete Illustrated Guide to the Home Aquarium, by Gina Sandford and published by the always impressive Dorling Kindersley press (renowned for their clear information design and beautiful photography), is a marvel of instruction and advice. Cross-referencing the two books is as much fun as learning the concepts.