Robert Schwalb has produced some truly amazing supplements and adventures for Shadow of the Demon Lord, but one of my favorites is from his Poison Pages line, Dark Passages, and features random table to create mysterious and diabolical books for your campaign.
Here is one I rolled up:
The Chthonic Verses of Eldridge Plinth is a slim book of about 100 pages with a cover that is worn and stained. The cover is made from a dark redwood and has thin spikes of brass forming an unpleasant glyph that causes a wringing in the reader's ears. The pages are a heavy paper from the mills of far away Pyrus, imported special by Plinth. The Verses are in a neatly printed Dwarfish and was penned with a water based, brown ink from the Drome underground river. The Plinth's tome is free of illustrations of any kind and is infamous for the author’s screed against Dhalripple Ferrodrang for his improper techniques at crafting aqueducts in Appendix V.
If the reader can break Eldridge’s cypher in Appendix Q, they learn the Earth Tradition Incantation, Earth Spike at Rank 0.
However, the book is infested with toothy, parasitic worms. A creature that opens the book must get a success on an Agility challenge roll with 1d3 banes or take 1d6 damage from the burrowing parasitic worms. At the end of each round, the creature must get a success on a Strength challenge roll with 1 bane or take 1d6 damage. After three successes or the affected creature takes 10 damage or more from fire, the effect ends.