If you have read any of my posts, you know I am new at this and am reading everything I can (here and elsewhere) to come up to speed. Not sure if there are others like me reading this forum, but while doing some searches on the net, I came across a short online course that has been VERY helpful. The course appears to be free and I am in no way connected to this site. The author does sell a book version of the course that contains 2 additional chapters, but I am only on chapter 2 of the online version and don't know if the additional chapters are worth it.
Here is the link if you are a newbie at digital photography and are just lurking in hopes of learning more: http://www.shortcourses.com/using/
(hope it is ok to post links to other sites - if not, feel free to delete this post)