I'm focusing on an internet site i'll prefer to know the amount of individuals who has visited the web site. Can someone let me know how to proceed?

Use google statistics: http://www.google.com/analytics/

I'd provide you with a code to place but to tell the truth the best choice is by using something similar to Google Analytics. It offers a superior an excellent analysis of the website visits and it has many features that will give you a really very long time to build up

Since you've labeled this with asp.internet, I presume you are running on IIS. Make certain logging is enabled for that site you are dealing with and you can determine in the log files the number of customers are visiting your website by IP addresses.