it's not complicated actually...
you can find all the resources needed at xda developers forum...
at the moment i'm using cm9 (ics 4.0.4), last updated 22/05/2012...
but i change the launcher from trabuchet to apex launcher...coz the trabuchet is a bit lag with the animation/effect when scrolling...

the battery seems good, normal usage with data plan enable & facebook update, email update, making call & internet browsing, the battery could last for the whole day...
later charge it back before sleep at night lor
and i'm on BL7 kernel...

if u on BL7, you'll need to install the rooted stock rom first...

then u need this stuff:

1. 2ndinit...
2. latest cm9 (i'm using the Quarx version, they said it's better than epsylon version, but i never tried epsylon )...

then just follew the steps here: http://forum.xda-developers.com/showthread.php?t=1618904

good luck...