[CentOS] Building packages using RPMBUILD

I have been following the MaximumRPM guide from here:

http://www.rpm.org/max-rpm-snapshot/index.html

and it seems a bit dated, but still very good (if fact the best all round documentation I have found so far) on using RPM package manager, and how to build rpm packages.

The guide tells me to use the original paths, yet Centos wiki says otherwise.

[rpmbuilder@karsites sox]$ rpm -iv ./sox-12.18.1-1.src.rpm error: cannot write to %sourcedir /usr/src/redhat/SOURCES

Is there a package I need to install and run to set things up corectly?

I have created a user called 'rpmbuilder' under my home dir, and created the rpmbuild dirs under that.

So what build dir shall I go for?

Kind Regards,

Keith Roberts