I've found the main reason people look to vectorize their code is for speed. That provides a hint of what keywords to look for when searching for a guidebook. With the understanding that not everything written for Matlab applies to Octave, and vice versa, some of the following have been useful:
Writing Fast MATLAB Code - Pascal Getreuer 2009
Matlab vectorisation tricks
And one of my favorites
Peter Acklam's MATLAB array manipulation tips and tricks