i need complete information how to design a web application i want to develop a website of a medicine compony i wish to work at symptoms of different diseases the application should return related medicine and name of that disease also biodata,a security system also included to application if this not included then every user will be itself a doctor.plz guide me

You could buy a bunch of books and spend a year reading or you could hire someone to build the site for you.

The best you can do is hire someone and not to loose time and money working on this by yourself.