> Anyone have suggestions on best practices for long term water storage
> (i.e. how to treat the water for storage, when to rotate it, etc.)?

Here's the word from the Alameda County Water District. It's in the San Francisco Bay Area and is geared toward storing water for the inevitable earthquake>

http://www.acwd.org/faq.php5?category_id=57

I think it answers your questions that I've repeated above.