Hint For Defeating Andariel:
As you approach the Level 4 Jail there is the room that is filled with dark ones and some fire mages. Defeat them all by just running and killing first, the Shamans and next the projectile enemy fire mage. The other room next to this will be the room of Andariel the Queen. When I encountered it she had only 4 Dark Ones. With a Dark Shaman beating the 4 dark ones makes things easy. Fighting with Andariel face to face is too hard, so you better go back to the encampment and hire a 60 life Rogue to keep her busy. Stab Andariel from behind and presto your in ACT II. Then return to Andariel and the first thing you have to do is to sneak behind Andariel and blow her out as your Rogue (who you hired) is busy with her.