Sharepoint 2010 Basics

How to Create Web App
http://blogs.salmanghani.info/create-new-web-application-in-sharepoint-2010-part-1/

Create Site Colletion
Application Management > Create Site Collection

The simplest KNOW HOW
How to Create Web App, Site Collection and Website
http://technet.microsoft.com/en-us/sharepoint/ee518671.aspx