I'll bite, while I wait for help on my query. First, are you set up ok? Are you generating some basic sounds?

I'm not sure exactly what you mean by "in both the frequency and time domain", so I'll just blithely ignore it, and assume that you want to make tones with overtones. Or chords. Doesn't really matter.

I'd say read the Chapter 1 from the book. That's what I'm working on right now. It's available for free, here:

http://www.csounds.com/chapter1/index.html

All you need to do is get to "etude 2", where it gives you a few simple instruments to play with. You could create overtones by laying out simultaneous sine waves, like so:

; P1 P2 P3 P4 P5 P6
; INS STRT DUR AMP FREQ WAVESHAPE

i 107 0 1 10000 440 1
i 107 0 1 5000 880 1
i 107 0 1 3333 1320 1

and so on...
(note how I'm tapering amplitude by 1/n, which is my personal arbitrary preference for overtone "blend")

Also, you could play with the instrument in etude which uses the "buzz" opcode (i 109? Don't have that in front of me) which allows you to simply specify how many overtones you want.

So, the bottom line is read that chapter, and it'll give you the basics to get started.