Can anyone give me a thorough explanation of some of the FFMPEG commands?
That's a very general question, you will have to ask for a specific command if you want help since ffmpeg has a loooooot of options. But you can use the following command to get help:
-h      -- print basic options
-h long -- print more options
-h full -- print all options (including all format and codec specific options, very long)
-h type=name -- print all options for the named decoder/encoder/demuxer/muxer/filter/bsf/protocol
See man ffmpeg for detailed description of the options.

If the output is to long you something like: ffmpeg -h |more
And it shows a part of the text on the screen everytime you pess a key...