Dive Into Python has a chapter. Can't vouch for how good it would be though.
Isn't pulldom is a tool for parsing XML, not generating it (which is what the question asks about)?
To complete your answer, can you add that lxml also support XML schema and XPath, which is not supported by ElementTree? And it's indeed shipped with Python 2.5.
ElementTree is good until you need to deal with namespaces then it falls apart and it's unusable.
In Python, there are others ways, such as ElementTree (see Gareth Simpson's reply)