Installing a library from sources in Linux and Unix is the same as installing a normal app from sources. You download and extract the archive, cd to the directory, ./configure, make and sudo make install.
The right place for installing a library is /usr/share/lib.
When you compile a library from sources (with ./configure, make and sudo make install) , it will be installed by default in the right place: /usr/share/lib.
To find out what libraries is a program using, use one of the following commands:
$ ldd path/to/the/program.
$ lsof -P -T -p PID #PID is the process id of the running process/aplication