bippym is definitely right in that it's worth doing some reading.
However, what I'd say from my experience is you don't need to do vast amounts and you don't need to read any of these book cover to cover, dip into what you need to know and what you find interesting.
As a minimum you could try reading some or all of this:
http://amiga-manuals.xiik.net/ebooks...0eBook-ENG.pdf
and this:
http://amiga-manuals.xiik.net/ebooks...0eBook-ENG.pdf
and just start coding!
In my opinion, anyone who does all theory and no practice will never learn to code - the real learning is in the doing...