Learning Moose, Catalyst, and DBIx::Class all at the same time is like trying to learn Calculus and Number Theory at the same time as Algebra. Catalyst is an advanced application of object oriented design. DBIx::Class is also an advanced application of object oriented design. Moose is a framework for implementing object oriented design. And to understand Moose, you probably should have some basic understanding of Object Oriented programming.

You can probably pick up many of the principles of Object Oriented programming while learning Moose. But I would try to get a handle on those two things before moving on to DBIx::Class, and Catalyst.

The O'Reilly book, Intermediate Perl, and the book Modern Perl (free and purchased editions available) provide fairly good introductions to the basics of object oriented programming, as well as the use of Moose. There's plenty of room for more advanced concepts later, but they will get you started down the right path.

Once you're fairly comfortable with the basics of Object Oriented work with Perl, you will be much better equipped to comprehend DBIx::Class, and Catalyst. There's a book, The Definitive Guide to Catalyst that actually features a chapter on DBIx::Class, as well as additional discussion on Moose. The DBIx::Class manual is also very good... and eventually there's no way around it; you've got to read it.

For Catalyst... well, first, why Catalyst? I understand, that's what big business uses, but it may be a gentler introduction to MVC frameworks to start with Mojolicious or Dancer. And you may find that one or both of those fill all of your needs without ever diving into learning about the 700 pound gorilla, Catalyst. Nevertheless, The Definitive Guide to Catalyst is a pretty good book. When you do feel ready to dive into Catalyst, the Catalyst Manual is your starting point.