Kata, Step by Step...

Hey guys, first post here, so forgive me if my question has already been aswered elsewhere. I've clicked around a bit, and haven't really found what I'm looking for, though, so maybe you guys can help me out...

I very much enjoy working kata, learning its applications, and looking for new ones, but I feel restricted in that I only get a few hours a week to really practice my art under the supervision of my instructor. Often times I'll catch myself at home or at work walking through a kata, but when away from the dojo I don't get to enjoy the luxury of having someone there to correct my mistakes. Could anyone recommend a source, be it a website or a book, that I could use as a sort of step by step guide to different katas? I know that I can't possibly expect to pick up all those little details in pictures and text, but my instructor can correct my minor mistakes at the dojo. I'm more concerned with developing a more firm understanding of the basic steps of my kata...
At the moment I'm specifically interested in the Seisan Kata, Naha form...
Any help at all would be greatly appreciated.
Thanks in advance.

some links you may find useful:

http://www.gojukarate.co.uk/sodokan024.htm

http://www.fightingarts.com/ubbthreads/showflat.php?Cat=0&Number=221658&an=0&page=0

then you always have a google search:
http://www.google.com/search?hl=en&lr=&q=seisan+kata+goju+mpeg

I hear the best goju kata video is from around 1980 by Morio Higaonna (NOT his new 'technical series' ones). The DVD is called "Goju Ryu Kata". It is not instructional-it's for reference, he did this video like a recorded library of the kata (with some bunkai)...there is no talking or teaching. in my opinion, this is the best way since you should only use these as reference, not instruction.

This is a biased opinion since my Goju background was influenced (indirectly) by Higaonna sensei.