From LSWiki

Introduction

This is my Ringerwielder's guide, updating the advice found in the Newbie's Guide to a Ring of Power. I began serving our lord Ahrikol with Sinister Stairs and Ixithoth, and my current servant is Corvynna Kinslayer.

Joining

I haven't figured out what the precise joining requirement is, as I've been denied for both insufficient rune lore and lack of deeds; I think quest points are more important.

Easy quests you can do with no fighting include At'lordrith's Riddle, Death's Gate, the Devonshire Murder, the Inner Sanctum, the Lost Kentaur and the Source of the Slime.

The assassination quest has minimal-to-no fighting required. Gwalin's Quandary, Hardin's Gauntlet and the Dunwich Mystery require fighting, but they are routine and others may already have the quest items available for you.

There are other easy quests as well, such as trivia quest, but these are the ones that can be completed the quickest, IMO.