We've all done it. You create the web application in Central Administration and then immediately jump to the browser to admire your new site. But there's nothing there. This usually happens when you are trying to show someone how easy it is to provision a site with SharePoint.
Oops. We missed a step. You need to create a site collection before you will be able to see anything. Obvious, but you'd be surprised how often it happens during the quick demo under pressure.
Central Administration->Application Management->Site Collections->Create Site Collections. Don't forget to select the right web application.
Still not working? If you are using a port other than 80 you might need to check your firewall rules. Also you may need to configure DNS records. If you did that and it still can't resolve it, try doing an ipconfig /flushdns on the client.