Creating RPM from tar.gz

I'm sure there's a way to do this, but I am not experienced with building RPMs.

I have a tarball which contains the files and installation script for an agent that we want to install on a subset of systems. I've been asked to create an RPM in order to expedite the installation of this agent.

Basically, the manual process is to explode the tarball and then run the installation script and then the tarball and directory created from exploding the tarball are to be removed.

Is there a way to take this process and create an RPM that handles these steps automatically?