Non-build files under CVS control

[bill]

I'm relatively new to CVS, so this may very well be an old FAQ,
but I couldn't find an answer in the CVS FAQ at www.cvshome.org.

I have many files that must be under revision control, but that
are decidedly not part of our software's distribution.  (Most of
these files are Perl, Mathematica, and Matlab files that perform
various support roles during development and testing.)  These files
coexist in the same directories with the source files that are part
of the distribution.

What is the best way to arrange things such that, at build time,
I can check out only those files that are part of the distribution?

Many thanks in advance for your suggestions,

        -bill

P.S. A much simpler problem is several files that are part of the
distribution, but should not be under CVS control.  We deal with
these via .cvsignore files.  Just out of curiosity, is this the
recommended approach in such situations?