Nospam wrote:
Is there a good book (or website) such as "Trim Work for Dummies" that gives
instructions for replacing trip. I am looking for a little depth such as
what to do if the floor is not perfectly level, and how to square door
frames, etc.

Taunton's books are about the best I've found.
http://www.taunton.com/store/pages/070450.asp

As far as the base trim on an out of level floor, it depends on how far
it is out. I almost always use built up trim - at the very least a
shoe molding - so that takes care of the simple cases. If the floor is
out more than the shoe will cover (about a third of the shoe height),
then I start scribing the base to the floor. The only caveat with that
technique is if you're following the floor around the room and end up
where you started, the pieces won't necessarily align and then you have
issues. Shoot the floor with a laser, scribe your horizontal line and
run the base to that.

Squaring a door frame...I'm not sure I understand your question. It's
always easier to hang the door in the jamb and install it as a unit. I
use the door itself and a strip of hardwood as a spacer guage. If you
have an equal space on the top and strike side you have a squared
installation.

R