Confused about documentation and what's current

I came across an article at … 542-5.html about using Asterisk as an answering machine. My current solution is no longer being actively worked on, so I decided to see if I could make this work.

Since that article seemed a bit outdated, I tried using the Asterisk documentation – specifically, … P-3-SECT-1.

However, that document keeps talking about zaptel and I saw a reference elsewhere that says zaptel is now dahdi.

Since I’m a newb, should I just use the older procedures in that Asterisk online book? Or is there some other document that will help me learn my way around the newer release?

Book can show you some general concepts but then you can check examples. There are lot of examples. You can
make examples
and get all conf files with examples.