Ok, below is a link to a spreadsheet calculating knowledge devotion stuff.
Knowledge devotion is a feat from complete champion. Basically by taking an appropriate knowledge check on a creature (knowledge nature for animals for example), you get a bonus to hit and to damage. You must have at least one rank in the appropriate knowledge domain.https://spreadsheets.google.com/ccc?key=0Agyp18cKx2LZdGNaM3F2anJnMmZvb01fTmlwRE9nOWc&hl=en&authkey=CJi35O0F
Blue cells are good for editing.
Meaning of cells:
Unfortunately you will need to download the file or upload it to your own google docs account.
Why make a spreadsheet? I was debating between starting as a swordsage and a rogue (long story). Basically, a rogue gets 8 extra skill points that I would invest in knowledge (etc). Very roughly, these 8 skill points translate into one extra to hit and damage bonus, to creatures of one specific knowledge type.
For my case, starting as a swordsage would have preserved one point of bab in my final build and to me that is worth more than a one point bonus to hit and to damage a specific group of creatures.
Aside from this, the higher your knowledge check bonus and rank, the less benefit you gain from additional investment in knowledge skills. With stuff like, epic headband of intellect, lore of gods and scrolls of uncertain provenance, 1 point in any knowledge skill will get you a 4.35 bonus on average.