Scrolling down, you will find a series of mini-projects. Most contain written tutorials, others by YouTube video. The projects become increasingly challenging as you scroll lower. NOTE: A few of these tutorials require Script-Fu. To download this plugin, go to registry.gimp.org/node/186. There you can scroll down to "How to install (Script-Fu version)" for directions.
Motion Blur Effect
Wire Art
Changing Car Color
Photo Sketch with Balloon Text
Animated Car Lights
Animated Snowfall
Animated Swirly Water
Exploding World
Bling Text
Pressed Text
Splash Text Effect
3D Pop Out Effect
Fancy Glow Effect
Image Inside Text
Glowing Rainbow Text
Wind Blast Text
Animated Glowing Text
Glossy Metal 3D Text
Chrome Beveled Text
Smooth 3D Text
Golden Silk Text
Glowing Metal Text
3D Text

Click on image for YouTube tutorial.