Yamaha DTXpress/DTXplorer/DTXtreme

Good Morning to all :)

I was wondering if any of you guys know a good place to get up to speed on 
MIDI? I am struggling with a learning curve on some of the terms and 
abbreviations that are used. I am hoping that these are not Yamaha specific 
terms, since there is no glossary to speak of in the book. 

If someone could let me know a web site or a book/magazine to catch up on 
MIDI I would greatly appreciate it.

Thanks again,

Scott