Rooting Instructions are here, there is a possibility to make a backup of the reader beforehand, you have to look for it in one of the russian threads.
app2sd needs to be set-up additionally, but i've encountered a space problem
here. maybe you know a solution.
market is available somewhere, but you can
sideload everything you need, basically. the wiki was a good guide for me, since many apps will flash your eyes out, really.
you can update by flashing the newer AMR over the old one, I read in a rupor post on another thread around here.
Basically everything is covered by the
wiki.