if i have built html site in right navigation i want to add "releted news section" ,and they change automatically.. how can i build this type of code and add in my html site??
That will require some server-side coding in a language such as PHP, which I take it you don't have any experince in? If it's just a simple news system with a "related news" functionality, may I suggest trying WordPress (http://wordpress.org/) with what seems to be a popular Related Entries plugin (http://wasabi.pbwiki.com/Related%20Entries)?
creating your own html site is old..... now a days webmasters are using wordpress/joomla for quick services and saving time... you should also try these both instead of creating your own html site and adding related news section because you cant do this with html, you should have to learn php/mysql for doing this