Is there a preferred location to store files that we install on the system?
for example, if we download perl or mySql modules to compile/install, where is the best place to put them.
I am putting them in /usr/local/src.
/usr/local/src is a great place to put tarballs. That way when you untar them you'll have a directory for the program, and under that you'll do all the compiles. Perfect . And afterwards you can always delete the tarball to save space.
For RPMs? We put those in a new directory we've created: /usr/local/RPMs.