Information that you need first:
Contact name
The hook for your niche (my niche is ideas and paperwork piling up)
Then think of how you introduce yourself and business in person.
Follow up with what you want them to do (do you want them to visit your website, call you, whatever you want them to do)
What I do when I want to write a letter or email is I start typing my ideas. Then I create the letter. Then I critique it, and then do it again (is there a better, more professional word for this, does this make sense, is this too long?) Then I send it to my friend (she is really good at working with me and coming up with better was of writing things or telling me that it is perfect the way it is). Then I make changes again and critique again.
Remember no errors! You are representing an Administrative Service and if they find one typo or grammatical error they will not consider you.
Check out MailChimp at
http://www.mailchimp.com/ They have a free membership right now that allows list of 500 and 3000 emails a month. This will make it easier on you to add all your prospects and mail them your intro letter and then later you can mail them newsletters or special offers. Set this up instead of putting all of them in your current email contacts (that can get confusing when you already have so many contacts for your daily/weekly tasks.
Good luck!
Erika Glem
Advantage Administrative Solutions
www.advadminsol.com