I am having difficulty learning the basics of formats, integration, etc. I own both a Canon XL2 and XH-A1 and still haven't learned how to integrate the two. Some older footage is XL2, and I still like that camera for shooting speaker presentations. I use the A1 for handheld work, but I'm not getting the most out of either camera. I edit on FCP.

What is the difference between square and non-square pixels? What is the practical significance between them?

How do I learn about different compression codecs and how to integrate various formats?

What about converting for web use, or for creating DVDs?

I've heard lots about shooting SD for DVD production, but I haven't found a text book, or similar training tool, so I can learn in depth.

Any help is appreciated.

Start with http://www.adobe.com/designcenter/premiere/articles/dvprimer/dvprimer.pdf

See Adobe Design Center - Galleries, articles and tips on motion and interactive design (http://www.adobe.com/designcenter/) for a bunch more.

These articles are a good starting point; Google for more specific knowledge.