Complete Backup of Kaiser

[marceoks]

Hi, Im new to Windows mobile 6 world and i wanted to know how to make a complete rom backup of my kaiser. I wnat to start tweaking my unot, and installing and playing with the different roms posted in the forum but first i want to be sure i will be able to go back to the original version. Is posible to do this? Can I completly ruin my Kaiser by installing a bugged rom or by having problems when flashing a new rom?
thanks in advanced!!!!