Sunlight and sky modeling

Sorry if its too beginers question ,but in beginers forum I didn’t get answer during the week:

I need some practical tutorial with code samples about sky dome(with lighting effects) and some realistic sunlight modeling
tutorial for 3D scenes(projected with glFrustum(…)).
Actually sunlight is more less clear to me and I did some basic lighting,
but with sky dome I need to learn - I don’t even know how to do coordinates correct.
I looked in Google,but it’s takes a lot of time to find smth really practical for coding.I looked in “”,they have
a great screenshots - exactly look that I need,but no informatiom how to implement it.
In there is also a very short and too “dry” information.

Here’s a skydome tutorial I found via Google. . .

The source is in Java, but the code in the accompanying .pdf document is in C.