The Editors Canada website provides information on different kinds of editing and several resources to help you locate the right editor for your needs and create a contract for editorial services.
University Policies Regarding Editing of Dissertations and Theses
Only some universities have a university-specific policy regarding the editing of a dissertation or thesis by a third party. Usually only proofreading is allowed, i.e., no substantive or stylistic editing. Many Canadian universities are in the process of formulating a policy and in the interim follow the Editors Canada Guidelines for Ethical Editing of Student Texts, a set of guidelines for editors on the ethical editing of a thesis submitted for credit towards a doctoral or master’s degree. If you would like editing assistance with your dissertation or thesis, you should first ask your academic supervisor whether your university has its own policy. If it does not, I would base my editing contract with you on the Editors Canada Guidelines. Under these guidelines, your academic supervisor must grant permission for professional editing.
The University of British Columbia
Simon Fraser University
New Zealand University Policies Regarding Editing & Proofreading of Doctoral and Master’s Theses
University of Otago: http://www.otago.ac.nz/administration/policies/otago011276.html
Victoria University of Wellington: http://www.victoria.ac.nz/fgr/current-phd/thesis-guidelines#presentation
University of Auckland: http://www.auckland.ac.nz/uoa/cs-pg-doc-theses-dissertations
Resources for Writing
These sites provide guidance on grammar, punctuation, structure, and style.