Creating a web application is the primary step for setting up a sharepoint site. When you think about Sharepoint Web Applications the first two questions that come up are:
Once those basic questions are documented we can start the process of creating the web application.

1. Go to SharePoint Central Admin site
2. Got Application Management Section and Click on Manage Web Applications

WebShare1.gif

3. In Web Application Management Page click on New

WebShare2.gif

4. In Web Application Creation Page
5. Set the Authentication Mode

WebShare3.gif

6. Set IIS Site Settings

WebShare4.gif

Specify the Name you want to see in IIS.

Specify host headers if you have anything.

Specify the path of virtual directory according to your organization standard.

7. Specify the Authentication provider

WebShare5.gif

By default use authentication provider as NTLM otherwise make sure you need to use Kerboes. If you are using a secured socket layer then set it to yes.

8. Specify the zone and server URL.

WebShare6.gif

9. Specify the Application pool Name and Identity.

WebShare7.gif

10. Specify the Database Server and Content DB.

WebShare8.gif

11. Specify the failover Database Server.

WebShare9.gif

12. Specify the search service.

WebShare10.gif

13. Specify the State Service.

WebShare11.gif

14. Specify

WebShare12.gif

15. Click OK.

16. You will then get the Success screen.

WebShare13.gif