Some websites offer so much good stuff that it's hard to find it all in one visit. NASA's website is one example of that. Every time I visit it I discover something that I hadn't seen before. My lastest discover on the NASA website is a series of four free posters and slideshows. These double-sided, 24" x 36" posters feature data, satellite images, graphs, and pictures about air, water, land, and ice. All of the images, graphs, and information on the posters are also available in slideshows created by NASA. The slideshows can be downloaded as PPT files.
You can download these posters for free, but to print them you will need a printer that can handle large paper. If you don't have a printer of the appropriate size you're not out of luck. You can use the Easy Poster Printer freeware to print the posters in 8" x 11" sections.
Applications for Education
If these Earth Science posters were just posters, I probably wouldn't have written about them. The fact that NASA makes all of the posters' information available in slideshows convinced me to share them with you. After going through the slideshows with your students the posters provide a permanent artifact that you can display in your classroom to reinforce the information from the slideshows.
Here are some related items that may be of interest to you:
NASA Space Place - Where Science is Fun!
NASA Images - Embed Galleries of Images and Videos
NASA Quests and Challenges