Research Opportunities? Email Etiquette?

<p>I am a sophomore majoring in Economics and I would like to start working as a research assistant in my fourth semester. I plan to contact professors in the Department of Economics, Applied Economics and Management, Policy Analysis and Management, and maybe the ILR School. I'm open to any sort of opportunity.</p>

<p>Does anyone have any advice about approaching professors via email? Are there any mistakes that I should avoid? Would you suggest attaching my resume and transcript with the initial email that I send across? If you can think of a specific professor/institute to contact, that would be wonderful too.</p>