i usually range them with knives or javelins they drop, just use a antifire shield and stay outta melee range. you can stay there for like forever like that, all u need are antifire potions
u can do it without the quest, but doing the quest helps because then u dont have to pay to get into ghosttown, which takes up another inv space. the quest also allows you to have an ectophial, which will teleport you to the green fountain(forgot name)
after you recive the books, u use the 4 different pages of the god book on the book to complete it. then you can read encantations and blessings with your book