What exactly are you asking? Do you need to know a programming language, game engine, 3d modelling program? Please be more specific.
As for
Quote: "the best software to use for good designs in 3d graphics."
There is no "best software" for creating 3D graphics. Depending on price, ease of use, and flexibility of the software, one person's "best" choice may not work for you.
Here is a list of modelling programs -- I use Blender, but many people find Milkshape or Wings 3D easier to learn.
I have CDO. It's like OCD, but the letters are in alphabetical order, like they should be.