1st: its appreciated =)
about the wolf. right click on the wolf's icon to summon it, he'll start just like us at lvl 1, go to the mangyangs and kill a few of them and he'll lvl up. As he lvl's you'll go to harder mobs (doh

), when he is around 10 lvl's below you, you can use him on your normal mobs.
To heal him you can use the recovery kit's (the ones you use for horses)..at higher lvl's you'll need HGP pots (those are the yellow ones at stable), they will recover 10% of your pets HGP..also is there the grass of life, it costs 50K and will revive your wolf when he dies.=)
note: if you have your wolf summoned, he'll get his own xp so you wont loose xp or something like that^^..
If you got more question's just ask me.