Added background image resources.

index.html

@@ -1778,6 +1778,15 @@ <h2>Position: fixed</h2>
 
             2. Add a different background image for the home page.
 
+            There are a few background images in your project folder to choose from or check out these resources for free images:
+
+            * http://superfamous.com/
+            * http://www.gratisography.com/
+            * http://littlevisuals.co/
+            * http://nos.twnsnd.co/
+            * http://unsplash.com/
+
+
             Your pages should now look similar to [example 10](project/examples/exercise10-home.html).
         </section>