Electro Magnetic Spectrum
https://imagine.gsfc.nasa.gov/science/toolbox/emspectrum1.html , this website informs you through the eyes of NASA. It gives you the definitions of everything involved with the Electromagnetic Spectrum, making it easier to fully understand. It asks and answers very good practical questions. It gives very good examples and pictures to look at while reading this webpage.
http://earthsky.org/space/what-is-the-electromagnetic-spectrum , is a site that goes deep into optics focusing on more than just the electromagnetic spectrum. It discusses why, how and what exactly the electromagnetic spectrum does and how it affects us. It talks about what colours you see through certain light and why. It also brings up the topic of the telescope and what certain things look like through the telescope with the electromagnetic spectrum applied. I thoroughly enjoyed going through this website because it went into more subjects like Black holes, which I find very fascinating.
“Invisible Universe: The Electromagnetic Spectrum from Radio”, is a book in partnership so you know you are getting advanced facts. It introduces students to the topic of electromagnetic spectrum. It teaches you how astronomers study the sky by detecting invisible light. It discusses invisible and visible light, and goes in depth on gamma ray bursts. It makes learning something so complicated sound so interesting.