limbo - 12:18 pm on Dec 17, 2008 (gmt 0)

Specifically for website design I'd also require a site map - this shapes the navigation, gives an ideas of size and page type.

To help gauge this, in tandem with the site map - a wireframe with site-wide navigation/sub navigation/and content regions should be approved as early on as possible.

It is also worth mentioning that most projects of any substance require a series of page types to be designed - so specify the number of page types you need to be designed too.