Here is a collection of interesting stuff about DWDM (basic). Those are just more interesting areas.
1) Spectrum - "I do not see any light coming out from that fiber!" NEVER EWER LOOK INTO THE FIBER!
2) Optical bands - fancy numbers for subcolors of infrared light.
3) Calculating - fiber loss on a paper
4) Dispersion - so what is this thing anyway?
5) QAM, QPSK - that is best explanation I was able to find.
6) Troubleshooting DWDM circuit - that is one way how to remotely find faulty part on the span
DWDM Gear:
Just in case - Power Calculator, and another, latency of signal in the fiber and other stuff.
Fiberoptics Fundamentals Almost 1 hour of MIT lecture. Very informative.
16dBm power can damage connector by pitting
http://www.fiberoptic.com/newsletter_images/specs/bicsi_news-best_practices.pdf