For umbraco versions:
Not Version relatedMIsc
If you are interested in contributing a Book, but don't know what to write, here is a list of ideas, just grab one and write it! (Also some basics about Books and HOW to contribute them)
Anyone who knows something about using umbraco and has a little bit of time to construct an easy-to-understand Book about it should definitely contribute. If you have figured out something cool, written an awesome XSLT for a common task, or successfully done something arcane or difficult which you think others would benefit from, please share!