The webpage you referenced is using PHP. Realize that sites will use PHP or ASP, and very rarely if ever, both. You don't want competing scripting languages such as those two going at it.
You might look on Google for some free apps to do your webpage design in, graphics, etc. Its been a while since I've done anything remotely in the area of webdesign, but I know the free software exists. Look for something free in the graphics department too, because you don't want to buy a full copy of Photoshop at $600 and then have to take on the learning curve just to be able to use it if thats not your main focus. However, Dreamweaver I would agree with, though not free obviously.
The webpage you linked to also uses a complete backend system with SQL of some sort. Do you want to go that far? I would tell you to look at some sort of Content Management System (CMS). There are MANY to choose from and MANY of the top rated ones are free.
http://cmsmatrix.org/ will have a lot of comparisons for you.