Make your resume and resume differ from those of other candidates. As such, you should never start your resume with such general salutations as dear sir, or dear sir. Normally, when a company posts publicly a recruitment ad, it will surely address the name, address and contact number so as the resumes may be sent to correct address.
Focus on the most importance: A resume or a resume both requires focusing points. You should go deeply into the most important points about your qualification and knowledge about the job and the company. You may make bold or italic important points (if printing).