Noindex = You are telling Google not to index that page. This is usually not a good thing if you want the content to be found in search engines. If it is a specific page, image or what-not that you don't want indexed by Google use NoIndex. If you want it to be able to be found, don't use it.
Nofollow is used in links. It is telling a search engine that you don't want it to follow the link you are posting. When a link has nofollow attached pagerank or anchor text isn't transferred.
