I found it great, but haven't been able to find any in the series. Any help?

Do you mean "Centaur Aisle", one of the Xanth series by Piers Anthony?
If you do, there are a whole slew of books. Here is a list of the books in the series:

1. A Spell for Chameleon
2. The Source of Magic
3. Castle Roogna
4. Centaur Aisle
5. Ogre, Ogre
6. Night Mare
7. Dragon on a Pedestal
8. Crewel Lye: A Caustic Yarn
9. Golem in the Gears
10. Vale of the Vole
11. Heaven Cent
12. Man from Mundania
13. Isle of View
14. Question Quest
15. The Color of Her Panties
16. Demons Don’t Dream
17. Harpy Thyme
18. Geis of the Gargoyle
19. Roc and a Hard Place
20. Yon Ill Wind
21. Faun and Games
22. Zombie Lover
23. Xone of Contention
24. The Dastard
25. Swell Foop
26. Up in a Heaval
27. Cube Route

There are also a few "combined" books that contain multiple Xanth novels and a Xanth encyclopedia. I have to admit that I have only read through "Man from Mundania".

I think that most of them are available from Amazon, either from the main site, or through the zshops network. You can probably get most of them used.

I hope this helps.