What are the important point you need to care about a covering letter?
Address the letter correctly. Spell names and titles accurately. If you are unsure of any details phone the company or the contact person given in the advertisement to ask for more information. If you do not know the name of the contact person begin your letter with 'Dear Sir/Madam'.
Be brief and to the point, trying to keep to one page where possible. In the first paragraph, include your objective, how you heard about the position and the specific position you are after. If you have researched the company mention why you are interested in working for the company.
The last paragraph should encompass your closing argument, why you want the job, why you would like to work for their organisation (i.e. if you have researched them, you may know of their views on corporate, environmental or social responsibilities.These views or other information you may gain may be compatible with your own, if so say so!).
State how you can be contacted and request an interview. Finish your letter with 'Yours sincerely' if addressing the letter with the name of the person, or ‘Yours faithfully' if you do not. Type in your name and follow this with your written signature.
An introductory letter requires a different approach. Consider it an employment proposal or business case - you're asking an organisation to invest in you, so you have to prove that the investment is worthwhile. More importantly, you need to prove that they can't afford not to employ you. To achieve this, ideally you want to identify a particular need or problem that the organisation is experiencing, and offer your expertise as a solution. While this approach requires a considerable level of research and time, it is a natural extension of a successful networking approach.
Your letter should present you as confident, in control and professional. It is vital that applications are mistake free. Spelling errors, grammatical mistakes or using the wrong words are irreversible mistakes that will see your application heading for the rubbish bin.