AussieJosh writes...

I usually make the cover letter the body of the email and just attach the resume.

Personally I hate this practice.

Nothing demonstrates attention to detail like a properly typeset letter with kerning, a nice typeface, etc.

A plain text email doesn't say anything about the person applying beyond the words themselves.

Or you can just do what most people do and write in your resume that you have "attention to detail" while simultaneously making glaring grammatical and spelling errors in said document – i.e. not demonstrating that skill at all.

I think a quick note in the body of the email that says "please find attached my resume and a covering letter and position XYZ..." should suffice.