I got a used CAD3 and it has shimano 600 shifters.
My problem is that I just cannot tune it just right so that I don t get a chain 'kling' on the very top or very bottom gear.
... May I mention that I am not very familiar with bicycle vocabulary...
So I can either get it without chain 'kling' on top gear but when I switch to lowest it start to kling...
I am a real moron, I should just go read a book about how to express myself. In the meantime, does anyone understand what I am trying to say? I keep on adjusting the cable wether if I climb.
Not sure what you mean by kling. Is the chain dragging on the front derailleur?
You should not ride "cross-chained, largest chainring with largest cassette cog, or smallest chainring with smallest cog.
Find the derailleur adjustment instructions at the Park Tool website http://www.parktool.com/. Do each step in sequence being careful to not leave anything out.
A great source for vocabulary and mechanical help is http://www.sheldonbrown.com / Harris Cyclery. Sheldon has been a terrific source of cycling information and advice.
The secret rule in bike gearing is that you really can't use at least two of the combinations on your bike. This is what Al is talking about with cross-chaining: when the chain is on the small front chainring, you will not be able to use the smallest rear cog; likewise, when on the largest front chainring, you will not be able to use the largest rear cog. So your 12 speed is now a 10 speed.
That said, one thing I've found when adjusting shifting on a bike new to me is that the front derailleur often gets tweaked out of line with the chainline / chainrings (twisted on the seat tube). If this is the case, lining it back up could give you one of these gears.