Application materials may be emailed or mailed. You should determine which is appropriate by reading the job posting, considering your audience, and/or consulting with someone in CPD.
If you are emailing materials, make sure that your email is flawless. This is the first impression that you make on an employer. Your email should have a specific, clear subject line identifying the job for which you are applying. Keep the e-mail short (2-3 sentences is plenty) and include all requested materials as attachments. Make sure that each attachment is easily identified by its file name (e.g. “John Smith Resume”, “John Smith Cover Letter”).
If you are mailing materials, always send job application materials in a flat envelope, even if it's only a one-page cover letter and a one-page resume. It's easier to read (and photocopy) materials that aren't trying to fold in on themselves. The bookstore sells single flat envelopes.