I'm new to DNN so forgive my ignorance. I have setup DNN and set our main website up. Everything is running fine. I want to add a new portal for a client. However I'm not quite understanding some things and can't get the puzzle pieces to fall into place. I can log in and create a new portal, but when it finishes creating the portal, and tries to direct to the url i set up as the portal alias, it doesn't take me to the dnn site for that portal. I'm not exactly sure what i need to do at this point. Do i need to change something in DNS? Do I need to create a virtual directory or application in IIS? I've tried a couple different things, but nothing seems to work so I'd appreciate any help. 

Thanks so much Chris! My DNS was ok, but I had to add the host header. That was the part I was missing. Adding the host header for the domain looks to have cleared it all up.