I saw this link mentioned on a homeschool forum recently and had to share. We do timeline activities each week and have found that they look so much more interesting when we use pictures. ClipArt, ETC. has thousands of free clip art to download and use. These are great for timelines, notebooking pages, lapbooks, reports, and more.
Then, as a bonus, go to the bottom of that page and click on the resources. One link will take you to Maps, ETC where you can download maps, even historical maps, of many different places.
Clippix ETC takes you to a site where you can download pictures to use in presentations and reports. Many different subjects are represented.
Presentations ETC is a site where you can download free templates, backgrounds, and pictures for use on webpages, presentations, scrapbooking, and more.
And, finally, the FCIT website, which appears to be the mother site for all of the above, has a wealth of resources for homeschoolers - lesson plans, resources, and more.