Here is a list of free teaching resources on a variety of subjects including (but not restricted to) computer graphics:
- Udacity has a course on computer graphics and CUDA: https://www.udacity.com/
- There are many courses on this website as well : https://www.coursera.org/ . There was recently a course on CUDA with good lab exercises. You can browse the class archive at https://class.coursera.org/hetero-2012-001/class/index
- There is also online lecture at edx: https://www.edx.org/ .
For example the Graphics lectures by Ravi:
And of course you have lectures put online by current or former members of manao: