I've talked with Ulcaster, and went down to get the tome. I've explored several rooms and have come to a dead end. I know there are more rooms. I've looked at a screen shot of the entire dungeon map. There is a passage off the east wall in the room where you meet the wolves and get the poitions of healing. It is not on my map. Do I need to find a lever or something? Help.

If you mean the wall oppicite (don't mind my spelling im 15 and all) to the passage wich leads to the spiders yoou just have to got as far down as possible and just go east
eventhough you might not see the passage , it is there
but you cant see it because the wall is in front of it
There is nothing that u have to do to make the passage appere