If you know the name of the software, you can search for it:
apt-cache search plotutils
The headers to include are usually in a *-dev package. But even if the package is not installed, you can make sure:
apt-file show libplot-dev
Or if you know what particular file you are looking for, you can search for that, too:
apt-file search /plot.h
You can even see if there are perhaps multiple versions avaliable, and which one will get installed...
apt-cache policy gcc