I am new to SharePoint 2010 and recently ran into a problem after creating a new Web Application on my SharePoint sandbox server. I was able to create a new web application and add a site collection to it but I was not able to view the site in a web browser. After spending several days (not complete days) working on this I decided to post a question on the Technet form for SharePoint 2010.
Once I posted a question on the forum I found a link, in the forum, that contained the answer I needed. If you are faced with the issue I was, here are the links to the fix. The first one is the site that I found the link to Microsoft KB article on and the second is the actual Microsoft KB article with the fix.
Good luck.