Need beginner LOD tutorials to get me started

Hi

I am creating a 3D engine in C++ and OpenGL, but I am quite new building this engine and the advanced rendering techniques needed; as I want to incorporate a large and detailed cityscape. I have the models and they incorporate 400-1000 triangles on average, but as you know it will be too much in a rendered scene. I have heard of LOD techniques, which I admit havent started with, as I am new to LOD. So can anyone recommend me any beginner tutorial sites or papers they can help me to get starting on my own test work.

Regards
D. Wilson

Lod is simple, you make a few versions of the same model but with different poly counts, in your case it might be 1000, 600, 200 and 50 polygons.
Then you just choose one of them to render based on distance and resolution.

Thank zeoverlord, that is more than welcome. It seems so logical and striaghtforward. So I will work on your suggestion. Thanks mate