I have written some simple apps following the tutorials on http://learningwebgl.com. What is the simplest way to load and display Collada model files, particularly the files available from Google 3D Warehouse?
Have a look at the opencollada site.
The SDK is licensed under MIT license and should get you a good start.
If you are planning to make a game (and not just a viewer app), you should run the converter offline (during the build) and load your optimized model format during runtime.
Parsing collada is inefficient and shipping collada files is just wasted space.
GLGE supports viewing Collada. However, I would suggest converting to JSON offline and using that instead.