Full lifecycle help please


I am new to the forums, and fairly new to using OpenGL.

I am hoping that I can use some of the expertise in these forums to help me to decide how to begin tooling up for a complete graphics development system.

OpenGL seems to be the best choice for manipulating and integrating computer graphics. But I am at a loss for what tool or tools to use to create the initial 3d graphics in a format that is readily usable with OpenGL.

An Ideal tool would be able to read standard CAD formats and convert them, and then allow properties such as textures and colors to be edited.

Any help will be appreciated, and I appologise if this is not the right forum for this question but I do not know where else to ask it.