Different companies have different requirements for submitting a resume.
Before you send anything, be sure to find out what the company is expecting to receive. Knowing what to do when the company doesn t tell you anything is important. In general it makes sense to cover all the most likely bases. Make sure that you mention this in your e-mail, and give the company all the necessary information for viewing the files. If you also have your resume on the web as a .pdf file, then by all means include the URL in your post.