You can dramatically decrease the complexity of a web site project by separating the programming from the design. Seth Godin’s blog has some good tips:

Start with design. Don't involve the programming team until you're 90% done with the look and feel of your pages. It's cheap to change design if it can't by supported by programming, and cheaper and faster to have design done in Photoshop before you commit to cutting it up and coding it. [PowerPoint can also be used to create prototypes.]

From Seth's Blog: How to create a good enough website. Cited in the Globe and Mail, October 25 2007

James Robertson of StepTwo Designs agrees – in one of his terrific articles on Content Management Systems, he says that “organisations are almost always better served by separating out the design and the CMS, and sourcing these from different providers.”