Best Way to Add Dynamic Content on Pages

Hi all,

I’m trying to make a wordpress site with 4 pages and 1 blog page. A couple of the pages need to have a slightly different design. Is the best way to do this through the creation of different templates (currently using get_header in my templates)? Do I need use categories in my site? If so, how?

Also, what’s the best way to implement different content on the different pages(images on page need to change as does aforementioned header)?

Thanks in advance.