Omni:
Yes! GameDev has excellent ones...er...I don't have my links, but, um...two seconds...these are good...
Isometric and Hexy Stuff from Gamedev
Not sure if I can link to the articles directly, but I particularly enjoyed:
Isometric 'n' Hexagonal Maps Part I
Isometric 'n' Hexagonal Maps Part II
Introduction To Isometric Engines
and maybe that 'How to Cache Tiles in Memory Efficiently' article, or something like that.
I'd login, but...well, anyway. Not using my personal laptop right now...