Need help - tagging, branching, adding

[ferkee]

We hired a contractor to do a major upgrade to our warehouse
management system that I normally develop for.  I got everything "Up
to Date" in cvs.   They ported out a copy of the project, made their
changes off-site, then ported them back to our system.

I untar'd the source files (some were unchanged, some changed, some
new and there were also new directories).

Our directory structure pretty much follows this scheme :

proj/
     subsystem1/
                       src/
                       dat/
                       obj/  <--- .cvsignore'd

     subsystem2/
                       src/
                       dat/
                       obj/  <--- .cvsignore'd

and so on.

My problem is that I am pretty much the only developor so I have never
had to know a great deal about cvs...just doing status, log, getting
older versions, checking in, committing.   I have always wanted to
learn more about tags and branches but had a hard time grasping the
subject.

Anyway, I would like to be able to (I guess) tag all the "Pre-Upgrade"
code as such for whatever reason (in case we need to revert back all
the files, for posterity's sake, etc.).  THEN, I'd like to know how to
systematically put into CVS all the modified files, AND locate and add
any new directories and files.

Thanks in Advance,
John