Please just tell me what I need to include in my html doc to use the validate

Hi have inserted the html document I am trying to validate on the W3
site.  
I realize I need to declare the Document Type and would also appreciate
receiving that info/"line of text".
You will notice that the Document type has not been added to my doc.  
 
The major concern . . .
In the pass I have included the following line of text in my html doc to
validate on W3:
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1">
This text has been added to my document, however, it no longer works.
I would truly like to validate my document using the W3 site.  I have
only just begun writing it.  
Please advise.
Thank you for your help.
 
___________________________
Lillian L. Woodard
lillianwoodard@verizon.net