As a sales hiring manager for the last 6 years, I have been the recipient of many resume submissions. Over the course of time I have come across a few Do’s and Don’ts. 
DO:
1. Remember to attach your resume (Seriously. I get at least 2/week with no attachment)
2. Include a short concise cover letter IN THE EMAIL. Not once have I opened a cover letter attachment.
3. In this cover letter, tell me why you are the right candidate for the position. What knowledge, qualities or skills do you have that are well suited for the role?
4. Please, please, please submit a resume that clearly states what you did, what your accomplishments were, and, if you are in sales, quota attainment.
5. Spell check!!
DO NOT:
1. Don’t include the phrase “the birds were singing”, or anything else as equally non sequitur in the cover letter/email. This sets you apart, but not in a good way. This exact phrase appeared in a submission from 2 weeks ago. Needless to say that resume wasn’t opened.
2. Don’t include a long, tedious cover letter with no content. I can’t tell you how many I receive elaborating on what great sales experience the person has. Blah Blah Blah. Great sales people will tell me why their product (themselves) is the perfect solution to my problem (open position). And not in a cheesy way!
3. Don’t leave any grammar mistakes on the cover letter or resume. Seems simple, but showing an eye for detail on your marketing material will help show you can apply this same attention to detail on the job. The opposite is also true.
I know, not rocket science:-)