Wordpress Help! Need to copy menu style from one site to wordpress

I have a website that I'm trying to copy into Wordpress, I have everything except for the menu sorted out. The main menu has a header that changes on every page and I can't figure out how that can be done on a wordpress site. The original site was written in PHP and HTML, but transfering it to wordpress has proved to be a bit more of a challenge than I thought. Any help would be greatly appreciated. Winning bidder will get access to the site and can communicate by email. No milestones are paid out, but winning bidder will recieve payment in full once the job is completed and a tip, as all my freelancers do. Thanks -nate