what is the right keyword prominence and density that is used for optimizing a site? if i used 3 to 5 keywords on my meta title and use the other major keywords on my meta description do you think that is effective and won't harm my site?
It dependes on which search engine you are targeting. MSN and Yahoo! put more emphasis on keyword density in the title and page body, Google likes inbound links with keywords in the anchor text.
Now a days those theory is now a myth... You can spread your keyword in your content as long it would not look spammy or stuff.
I wrote an article about keyword density on my blog in August, based on a TV report on Google I saw, if it can be of any help Google and keyword density
Also, refer to this thread. You may find some of these answers helpful. http://forums.digitalpoint.com/showthread.php?t=1132930