tidy html & doctype

I need to tidy up my html and was advised by various search engines that there were erros on my html and had no doctype declaration - I could not find what my doctype was and a friend of mine said she thought it was html 4.o Transitional so I typed that in but I feel that it might be wrong I built my site in microsoft front page 2002 v5.1
but don't know where to look for the version of the html
This is all new to me so any suggestions are welcome.
Thank you

>From Beryl Arthur 
Bizzi B's Embroidery
e-mail <bizzib@mtuba.co.za>
          <bizzib@absamail.co.za>
          <beryl.theo@absamail.co.za>
          <beryl.theo@mtuba.co.za>
URL:- <http://www.bizzibsembroidery.com>
Address: P.O. Box 61,
               RIVERVIEW.
               3930.
                KWA-ZULU NATAL
                SOUTH AFRICA
Tel: Home - +27 035 5504006
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