Add site to Wordpress to act as CMS

We have a website [login to view URL] which we would like to put a CMS behind to allow our staff to easily add pages, edit content etc. We would also like a 'blog' page adding to the navigation so we can make regular blog posts. We decided Wordpress would be the best option and would also enable us to easily have blog page functionality. We will provide all the current HTML/CSS files. We will provide the hosting. We can install whatever is necessary for Wordpress to operate. We have designers available to do whatever design changes maybe necessary. If someone wants to suggest a Wordpress alternative thats ok, we don't have to use Wordpress if a better solution is a available.