There are several packages for preparing CCD data. All of them offer similar functionality. You'll find that it's easiest to use the package which complements the spectral reduction software you choose. There are two popular Starlink packages which you might use: CCDPACK and FIGARO. CCDPACK includes some tools for conveniently managing the preparation of many frames and supports the propagation of errors. It also has a GUI-based interface for setting up automated reductions. CCDPACK also has better facilities for combination of images, offering several estimators. In IRAF the noao.imred.ccdred package should be used for CCD data preparation.
Simple Spectroscopy Reductions