Welcome to the cross-compilation world, it's fun
I'd suggest you
1) download
QEMU disk, unpack it to any folder you like. Download
QEMU load image, put it to the same folder
2) download
POKY compiler set, unpack it to /usr/local/poky
3) get the
scripts for Anjuta-free development; tweak them to suite your paths
4) get hello-world, compile, put into QEMU disk, start emulator, iterate
5) tweak iRex/thirdparty projects
Additionally it is useful to download all available iRex sources for taking a glance or/and studying.