teaching aids

Hi!
I'm writing my Diploma paper on the theme "Teaching aids as motivating tools for pupils in forms 7-9"

Could you please advise me some books of web sites where I could find some division of teaching aids, for example, visual, technological?? or audio??

I have studied many books that describe each teaching aid but i can't find any categorization or classification!!!

Thanks in advance!

Linda

Here are three sites to start you off:
Teachers Choice International - Foreign Language Teaching Aids
Teaching Aids Tricks and Tools to Improve ESL EFL Learning and Teaching including multiple intelligence types, whole brain learning, suggestopedia and NLP
BBC | British Council teaching English - Methodology - Teacher as teaching aid