my guess is, burning crusades instances are kinda hard to find
party for these days anyway outside of guild runs, so no point
levelling as holy i guess. But it is possible and truthfully not
much harder or slower.
pala healing nothing much to read up... spam FoL, spec all the
talents that make yr heals faster, crit increase etc. crit for pala
is quite important cuz FoL is so small. otherwise its spaming FoL
and learning to target party members as quick as u can