This holy book is sacred to divine spellcasters of good alignment (LG, NG, CG). Study of the work requires one week, but upon completion a good spellcaster gains a +1 inherent bonus to Wisdom and one experience level—receiving enough XP to put the character’s XP total midway between the minimum needed for his new (higher) level and the minimum needed for the level beyond that.
Divine spellcasters neither good nor evil (LN, N, CN) lose 2d6×1,000 XP for perusing the work. Evil divine spellcasters (LE, NE, CE) lose twice that amount. In addition, they have to atone (see the atonement spell) in order to gain further experience.
Nonspellcasters who handle or read the book are unaffected. Arcane spellcasters who read it take 1 point of permanent Intelligence drain and lose 1d6×1,000 XP unless they make a DC 15 Will save.
Except as indicated above, the writing in a book of exalted deeds can’t be distinguished from any other magic book, libram, tome, or so on until perused. Once read, the book vanishes, and the same character can never benefit from reading another book of exalted deeds.
Source: Dungeon Master’s Guide (version 3.5), page 277.