there are so many teaching theories out there...
lots of information can be found on the net...
Some interesting theories are those of Gardner... the theory of multiple intelligences, but thats more focused on the learner.... ie. catering teaching for children with different learning styles... maths smart, linguistic smart, body smart, image smart etc etc...

this is a good list comparing various strategies that I used for an essay once...

http://www.adprima.com/teachmeth.htm

hope that helps....

mjp