It's been while since you posted this question but I noticed you had not gotten a response. Just in case someone has a similar question, here are my two cents.
If you have the opportunity to drop your resume off, do it. It affords you an opportunity to make a human connection and you are guaranteed that an actual person will have looked at your resume, even if it is just for a few seconds.
If you are emailing your resume, I have two suggestions:
1. Use the text from your cover letter as the body of the email. Attach your resume AND the cover letter (in the correct format). You just need to mention that you are attaching both. This way, if the recruiter or screener prints your documents for review, they will both look professional.
2. Write a short, effective email introducing yourself. It needs to have a bit of a hook so that the recipient is moved to open your documents. Of course, attach your resume and cover letter.
I hope that information helps.