When emailing a potential supervisor, should I offer to send them my researched material? I am currently finding a supervisor for an MSc program. It is incredibly difficult to get research experience as an undergraduate student (especially since I attend a large school with an incredible amount of competition). However, I make the best use of resources available to me. I have joined several organizations at school which are directly related to my masters program. As a member, I have researched and published several student papers (not in scientific journals). These papers are well written and researched (as they go through an extensive editing process) and demonstrate my passion. I will mention these projects in my emails / CV. However, in my emails, should I mention that these are "available upon request"?
As stated in comments, you should make the papers available to the potential supervisor online:


Create yourself a basic webpage with a sensible address. 
List the papers, with full details and references.
Link to the pages of the places they are published.
If the copyright agreement allows, link also to a copy of the paper.
Given the option, make this copy on the arXiv (get the supervisor from the paper to endorse you, assuming it's in their field).
If you cannot use the arXiv, store the copies on the same website.
Alternatively, your current institution may have an eprint system you can use.
Make sure your co-authors are happy with this.
Include the web address when you contact potential supervisors (if it is long, perhaps use a tinyurl with preview).