Can I get answer keys for the Exeter books? Edit
There are commentaries available, yes. You can feel free to email the chair of the mathematics department:
What resources would you suggest? Edit
Antiprism - A website that helps with visualizing prisms.
Desmos - An online graphing calculator. This has a pretty extensive list of tools, and is available in the iTunes store as well as on a PC with internet access.
Geogebra - Basically a free analog to Geometer's Sketchpad. Useful for students to immerse themselves in geometric concepts. Has algebra features, as well (hence the name, right?).
Playposit - This site allows you to upload videos from the internet or videos you've made on your own. You can then embed questions into the videos and assign them for your students to watch outside of class. (This used to be called EduCanon)
Zipgrade - This site is a potential replacement for Scantron machines. It allows you to grade multiple choice surveys, quizzes, test, etc. It also has the ability to track student performance on specific learning objectives as you move through a course.