cam2pc is able to extract and edit IPTC metadata from JPEG and TIFF files. IPTC metadata allows you to precisely describe the subject of your pictures and and to track the lifecycle of your pictures, this last option being more aimed at professional photographers.
All fields available are self explanatory so you can probably figure everything by yourself. The "templates" options can be useful if you always fill some data with always the same information. This will probably be the case for fields such as Copyright or Byline. In that case, take one random picture without IPTC data and fill those common fields. Click on the Save as template button and name your data. Next time you want to add IPTC data to a picture, first thing you should do should be to Load the fields from the template. Make sure this is the first thing you do as the template saves values for each fields even the ones that are not filled: when you load an IPTC template all existing data will be lost.