Any good design programs for pc  

I used to use sketchup a...
I used to use sketchup a lot, its easy and accurate and I wish the more serious cad programs would adopt some of its features.
But You'll never get a good render with sketchup, it will allways look cartoony.
If you can persist with 3ds max you'll be amazed, Autocad is good but is much more dry and better for cnc cutting and advanced engineering, 3ds max gives virtually photorealistic renders (I might put some of mine up) but there is a steep learning curve! But the best part is you can buy 3d models ( google turbosquid) and download them from many furniture manufacturers (eg. fritz hansen) and insert them into your scene, change the proportions and the materials...its endless. The absolute best thing you can do with it is simulate the movement of the sun throughout the day over a building or group of buildings and do a shadow study for a particular time of year and place and climatic conditions, great for passive solar design. And you can insert models into a photographic background and get them to cast realistic shadows on the walls and floors.
I got to grips with it by scouring the internet for free good quality models to download that gave nice renders, then when I opened them up I did 'print screens' of all the render setting dialogues and just played with the models and tools, back engineering I suppose.
But real life marquettes are much more tangible
this is not mine...