This page from Guide To Arts School.com is a very concise summary of what they consider the 11 best free photo editing programs. The page has links to the downloads for each app as well as links to tutorials for each application. In addition to the 11 download apps here are briefer links to their top five online tools.
A wiki to support "Using Technology with Classroom Instruction that Works" book...excellent resource of web 2.0 tools and how to use them in the classroom
Students can construct deep knowledge about a topic as they engage in building a multimedia project. If used effectively, a well designed student-driven learning experience can take the place of traditional methods of teaching content. Use of digital tools can provide students with flexible learning paths to meet their unique learning styles.