You'll find a book in the lair of the main boss of each street. For example, one would be in Lady Blackhope's house on Unicorn Way. You'll find that generally true of all book collections in the Spiral.
If you want to do it the easy way, the list of places is here in this guide at Wizard101 Central.
Look in the boss towers in wizard city. Where it says the location of each book is a street, just do all the bosses in that street until you find the book. (I had some issues with the one in Triton Ave. but found it eventually) :D
Anna Winterflame- lvl 50 balance Belgrim Foebreaker- lvl 10 Death