Where can I find out where a package has been installed to?

You can just use the rpm tool for this.

rpm -ql package-name

Will list all files installed by that package (that's que-ell).

You could open a terminal session and use whereis:

[linker3000@aa1 ~]$ whereis vi
vi: /bin/vi /usr/share/man/man1/vi.1.gz /usr/share/man/man1p/vi.1p.gz

The above will work but I found rpm did not work for development libraries (e.g. libssl-dev). It may have been me, but maybe not. Here is another approach:

If you have Synaptic Package Manager you can:

1. Locate the package under Installed.
2. Right click and select Properties.
3. Click the Installed Files tab.

This will show you where all the files are installed. An especially useful piece of information for development libraries that are installed in multiple locations.