The Iron Golem boss is considered to be a pretty easy boss, but that's not to say he can't be dangerous. He has high defense, but he's weak against lightning, so it's definitely a good idea to either get the Lightning Spear in Sen's Fortress (Mimic chest) or get a weapon enchanted with lightning. You can summon Black Iron Tarkus in the one empty room before the boss; just remember to be in human form if you want his help. The Iron Golem has one ranged attack, which is sending out a blast of energy that can knock you back; it's easily dodged by sidestepping. He will swing his weapon horizontally, kind of along the ground, sometimes going back the other way for a 2 hit combo; this can easily be dodged by rolling/running in between his legs. He can stomp the ground with his right foot 2-3 times, so just go around to his other side to avoid this (you can hit his other leg easily). His most dangerous attack, by far, is when he winds up with his right arm (the one with no weapon) and then grabs in between his legs; if he grabs you with this, then you will take some massive damage (one part damage when he grabs you, then another part when he throws you to the ground). You can avoid this by going to the sides of his body; if you roll in between his legs, there is a chance that he might grab you still, since his grab reaches a little behind him when he tries.