Wanted - OpenAccess figures on introductory molecular and cellular biology topics

Quick post here.  I am looking for OpenAccess figures on introductory topics in molecular and cellular biology like DNA, RNA, proteins, transcription, translation, etc.  I want these for multiple purposes including teaching, blog posts, etc.  Anyone out there know of a database of such things?

UPDATE
Some suggestions from Twitter

• NCBI bookshelf (from jewmanchue)