Modelling is easy. Good modelling is hard.
If it's something you wanna get into you are looking at programs like Blender, 3D-Max, Maya, Lightwave, etc. Heck, even SketchUp can be used though it's VERY difficult to get anything organic looking out of it (geared towards architecture).
That model you posted in your first post was most likely 2-3 folks and a week of work. It's very high rez detail and most likely multi layered textures.