I got myself up to date with carrara by using the "Carrara 5 pro handbook" by "Mike De La Flor". Though it was written for version 5 it can still be applied to the latest versions and actually helps to clear up some everlasting questions and reveals a few hidden secrets too. Once I had read the manual and completed the tutorials it was just a case of expanding what I had learned using the carrara help file, though I have to agree with you and say that it is lacking in true structure for the beginner etc.