Sometimes, people ask me what websites I visit when creating my PowerPoint slides, so I've decided to put all of my resources on this page for easy reference both for me and for you! Note that my linking to these sites does not endorse everything on these sites, nor does it imply that these sites endorse my work.
SlideShare allows you to share your work on the web and to see what other slide designers are doing. This is a great place to put yourself out there and to draw inspiration from other designers! It also allows you to easily embed your PowerPoints onto your website for easy access by your students.
Slides That Rock
I used to think that my slides were good. Then I visited Slides That Rock. Reading their e-book inspired me to take things to the next level. Since encountering Slides That Rock, I've started looking at slides more like art and not simply as a pragmatic tool for getting information across. A presenter's goal should be not only to inform, but to WOW one's audience. Bottom line: it's not enough to be better than most at slide design if your slides don't ROCK!
You don't have to be good at matching colors together in order for your slides to be visually appealing - someone who is better at it has already done the work for you! COLOURlovers is full of custom color palettes with RGB codes that you can plug in to PowerPoint for more attractive presentations. Once you get more comfortable, try your hand at creating a custom color palette
Garr Reynolds is a recognized authority on presentation design. Click above to read his "Top Ten Slide Tips." This site is full of sound advice for those seeking to improve their slide design skills.
Image Color Picker
Think you found the perfect color but you're not sure how to get it into your slide deck? Check out imagecolorpicker.com! Image color picker makes it easy to use colors from any photograph or work of art. Simply click your mouse over whatever color you like and you'll instantly see both the HEX and RGB color codes. This makes it really easy to make a color palette with colors that naturally occur in nature or that have already been matched by a brilliant artist!
Flickr has BILLIONS of photos to help you to find great photos for your slides. You can custom search for photos with Creative Commons licenses, which allow you to use their work for free under certain terms (these may vary from picture to picture). Great photographs will take your slides to the next level!