The best
word for liferay documentation and tutorials is "patchy". There are bits here and there. Javadocs do not exist. Finding anything takes digging.
The wiki and forum are hit and miss with regards to quality and freshness. One frustrating thing is that they have comments on the WIKI. So you have to read the Wiki article and then read through all the comments to make sure there isn't erroneous information in the Wiki article.
People have posted screencasts (
here, for example)
and
blog posts
The best way to learn is to install the
Tomcat bundle and the plugins SDK and try to make it do what you want. When you get stuck, ask a question here and we'll do our best to answer.