There are two different concepts of Amiga Development.
1. Native Development
That means, that you write and compile your program on your A1200.
For that I would recommend
Cubic IDE.
It comes with compilers.
2. Cross Development
That means you write and compile your Programs on Windows or Linux using Cross Compilers
For that I would Recommend
AmiDevCpp.
Download Page.
It can be used to compile programs for any amiga-like OS and for Windows too.