Thanks to Steve, N5SD for this link, and he requested that it be shared with the group! Here is a great link to help you learn more about most of the digital modes and you can also HEAR the modes which is VERY helpful!
From the website.....
"Click on the name of the mode (where the name is underlined) to hear an mp3 of how the mode sounds on air (these are to give you an idea of how that mode sounds, not for analysis purposes) I have included some sound files of mode variants - more to come as I find them)."
You can click the C4UCJ images above to get there or click