Professor Michael Alley has much expertise in the field of technical writing, and has developed several helpful templates for professional correspondence for engineers. Links to the templates can be found below.
Link to letter format: http://www.writing.engr.psu.edu/workbooks/letter_format.pdf
Link to memo format: http://www.writing.engr.psu.edu/workbooks/memo_format.pdf
Link to email format: http://www.writing.engr.psu.edu/workbooks/email_format.html
Link to resume template: http://www.writing.engr.psu.edu/workbooks/resume_template.doc