The requirements and guidelines for master's and doctoral thesis preparation and submission can be found on the Faculty of Graduate Studies web site, which describes the thesis formatting requirements, including the links to LaTeX class files, and provides examples of correctly formatted theses:
Thesis preparation and submission
Thesis formatting requirements
LaTeX templates – Michael McNeil Forbes
Sample thesis: traditional.

In addition to Michael McNeil Forbes' LaTeX templates linked to on the Faculty of Graduate Studies website (see above), there are other sources of thesis templates for LaTeX users.

The generic thesis class files can be downloaded from here:
ubcthesis.cls
genthesis.cls.

Graduate students in Mathematics have used the following tex and style files:
ubcmath-thesis.tex
ubcmath-thesis.sty
ubcmath-thesis-calc.sty.

In 2006, Adriana Tamae Dawes, a former IAM and Mathematics PhD student, posted sample LaTeX files of various thesis parts on her old IAM web page:
LaTeX thesis sample – Adriana Tamae Dawes.

In 1995, Anders Svensson, a former graduate student of the UBC Department of Mathematics, developed thesis and examination programme classes for LaTeX2e. These files can be used as templates for graduate theses as well as for the preparation of the final oral examination programme in LaTeX by doctoral candidates.
README file – Anders Svensson
LaTeX template: thesis – Anders Svensson
LaTeX template: final oral examination programme – Anders Svensson.