Not sure there is a answer to this. I think it varies with what your trying to achieve.

Do a search on the web or amazon for Scott Onstott "Enhancing CAD Drawings with Photoshop" its an older book but I think it will help.

SU - 3D, modeling, design work and rendering (although you'd at least need a plugin, like VRay, to make the rendering a high quality image)

Photoshop - take your rendering into Photoshop to add a sky, landscaping, people and adjustments.

PS - is a bitmap editing program, meaning it works with pixels and is geared towards "photo" like images (it has text and vector capabilities, but they are limited).


Illustrator - this is a vector based program. So, like Autocad, the lines and fills that make up the shapes are mathematical calculations. This allows you to scale the art work indefinitely, without losing any quality.

This is what a graphic artist uses for logos, so you can print on a business card just as easily as you can print on a billboard.

Autocad - Illustrator - you can take a floor plan from Autocad into Illustrator to pretty it up (adding solid walls, etc.). They are both vector programs, so you can bring the floor plans into Ill, make pretty, then export as a PDF (which keeps the vectors, allowing you to scale, zoom in, etc.)


(Note that you cannot do this with a bitmap image, like a jpeg, tiff, targa, gif)


The www.lynda.com tutorials are great, but you can also find tons of free ones here and there. Personally, I bought books and learned from there.
Nowadays you can probably find tons of free videos, too (I know Adobe has a bunch).

Thanks so much -- sounds like fun!