In the past, doorway pages were heavily used to help web site rankings, but the search engines have gotten more complicated and those web pages are not supposed to work any further.
Doorway pages are designed to have text intensive content with unusually high keyword content and links back to a web site. Usually doorway pages are stand alone web pages that link to the web site, but the web site does not link to it.
Search engines consider doorway pages as spam so avoid using them. It's better to put the effort into building your web pages with the proper content with a balance of images. Most importantly – update or add new content on a regualr basis. Give your customers and the spiders something to come back to.