Online resources for entomology?
The Entomological Society of America has dedicated page called Entomology Resources for Teachers, which might answer many of your questions. It compiles curated links to resources, universities, 

Here are a couple of other entomological links/resources that I have saved from before:


Bugguide.net
Pictures, simple keys and taxonomical info. Also has a forum.
The Entomological Foundation: Education
Links, project ideas etc.
Kerbtier.de
Webpage on beetles found in Germny, but relevant for many European countries. Also has general pages on e.g. beetle morphology and a glossary that might be useful.