Share some email etiquette (for sending emails to customer, employee, Client) - improving my writing skills

I have joined recently in a startup company as HR admin. And i am into my probation period. But exactly i don't know what to do as a Admin Executive. It is completely new for me, Kindly give me some guidance so that i can do my best. And could you please share some email etiquette (for sending emails to customer, employee, Client) for improving my writing skills.

Dear friend,
As a Admin Executive, to whom you report to? Sit with your reporting authority and discuss about your roles, responsibility and deliverable. This will bring clarity about your job.
Secondly, about e-mail etiquette. Lot of material is available on the internet. You could have referred it. More than email etiquette, you may refer ebooks on how to write the business letters. There are free downloadable books available on the internet. Read a letter every day and see the change in yourself.
Thanks,
Dinesh Divekar

Use the links provided on the right side of this screen.