First you need to install some software:
GCC ARM Embedded: https://launchpad.net/gcc-arm-embedded get the x_win32.exe installer
Mingw MSYS: http://www.mingw.org/wiki/msys easiest way is just get the installer here you can also download Mingw and add on MSYS.
Next install both, make sure in get MSYS.
Next Add the tools to your path for my system it came out as C:\Program Files (x86)\GNU Tools ARM Embedded\4.8 2014q2\bin and C:\MinGW\msys\1.0\bin
In most cases you need to have the msys path before %SystemRoot%\system32;%SystemRoot% stuff.
If all went well, then all you need to do is type make or make all and everything will build nice and easy
In terms of an IDE, I typically go with no IDE. I prefer using VI. so on windows i use gvim. download here gvim74.exe
Although you can just use Eclipse and select an external makefile when you import a project.