Hi Marty,

youtube is a great place to start when you are looking for any kind of instructions... including mixing audio!

Here's one of the many links you can find by searching on youtube for "how to mix audio"

https://www.youtube.com/watch?v=8eUOfinvxH4

likewise, you can search for sub-topics like "how to use EQ in an audio mix" (or compression etc etc)

Also, PGMusic has a youtube presence with a treasure trove of tutorials: https://www.youtube.com/user/pgmusicinc