Use Blender.

After you read 3 or 4 Tutorials you see it is very easy.
There is an export Script, that exports opengl code, too.
You modell it in Blender, then run a pythoon script and you get the glVertex3f() and glNormal3f() functions with the right coordinates. You can copy this direct to your C code.

for Blender: ask at elysiun.com

"Use Blender.
After you read 3 or 4 Tutorials you see it is very easy."

Are you joking? Blender is the most cluttered and overcomplicated program I''ve ever used, and I would not recommend it to someone with no clue. And they just keep adding to it and adding to it instead of trying to make it usable. Using it makes me feel like my head is in a blender! I can''t tell you how many times I have to quit out and restart it because I clicked a little button that pops up a whole new UI, full of more buttons that do the same.

the sad truth is, there isn''t really much for free modellers, not anything easy to use anyways. Wings3d seems to be the best or maybe 3d-exploration.