Sites with High Quality Photos You Can Use for Free | CSS-Tricks
Free photos. This list includes a number of sites I haven't seen elsewhere. Many of these just share a few photos each week, and you'd have to be pretty creative to use them for most corporate e-learning. This isn't just typical stock photos.
ChartTool - create nice looking charts with Image Charts!
Google Image Chart Editor beta tool for creating charts. Start from a gallery, enter the data, and adjust the variables. Creates html code for the charts (not a link to an image--the code to create the chart.
Design Comics :: Characters and Scenes for Storyboarding & Design
Free characters and office scenes that can be used for e-learning. Different expressions and poses for conversations. The license information is conflicting; it's labeled CC-public domain, but requests attribution so it should really be CC-By.
Online book about visual design for multimedia. The content is a bit old (originally written in 1996), but the principles of layout and color are still relevant.
Create Custom Characters for Your E-Learning Scenarios - The Rapid eLearning Blog
Tips on breaking apart and combining parts of clip art to create appropriate characters for e-learning, even if you aren't artistic enough to draw them yourself.