More than a year ago, I bookmarked this set of photography tutorials. Tonight, I stumbled upon the bookmark, and actually read one of the lessons. They’re cogently-written, targeted at the amateur and mercifully light on technical language. In the middle of the aforementioned tutorial, I found this great quote from Ansel Adams:
There are no rules for good photographs, there are only good photographs.
I think that’s true of a lot of things, particularly (but not only) in art. Consider this: “there are no rules for good pants, only good pants”.
DarrenBarefoot.com 
there are no rules for good monkeys, only good monkeys
My University has most of Ansel Adams negatives. A friend who was part of the photography department hated Adams with a vengeance and always discounted the work as “the stuff of a rich boy that had plenty of time to stand around waiting for the perfect shot.”
Always cracked me up.
Of course, the rules for good photography that I was taught by different professional photographs was to burn through film. Take as many photos as possible, and a few will be winners and keepers. Best advice I ever got, which is why when I do take photos, it’s usually like 100.