Could someone please help clarify something for me?

I am considering installing Gentoo PPC on a machine at home and would really
like to understand the install process better.

I realize that most of the issue is my lack of knowledge about Linux, but I
was hoping that maybe someone here would be willing to explain a few keys to
the install process.

First of all, what is chroot and do I have to do it if I install the stage3
tarball?

The docs said that you didn't need to do an emerge rsync with the install
since the stage3 tarball included the portage tree, whatever that is. I
guessed that it was the directory structure, but wasn't completely clear on
that. 

I tried to follow the directions verbatim, but there just seemed to be
something that I wasn't following right. The docs took you through the
stage1 and stage2 installs, but I got lost in what was supposed to be done
for the stage3. 

Any thoughts on the subject?

Consequently, I looked at the x86 install guide and it didn't look a whole
lot different from the ppc port, with a few exceptions, so I was hoping
someone here might be able to tip me off to where I went wrong.

Any ideas?

Thanks,

Chris