There is a help file on the same page as the CAW download, which is a basic tutorial. You will also find tutorials on many aspects of CAW here on the forum under The Sims 3 > Game Tools > Create a World > Caw FAQ's. The thread is stickied right at the top of the discussion list. It includes links to tutorials on other sites as well as on this forum.
I have made two worlds in CAW, but not from empty maps. I prefer to take existing worlds into CAW and edit them. It's much easier for me to make small modifications to terrain that's already made, and move, delete, and place new roads when there are already roads placed. There is a tutorial on how to do that too.