So you install a program with a GUI but there is no menu item or you'd like a custom entry for a program in the menu... — This is applicable for GNU/Linux desktop environments that utilize Desktop entries (.desktop) with freedesktop.org interoperability specifications
One thing that is helpful for me is knowing how to set up /etc/fstab to mount partitions at boot. This example is for a dual-boot with Windows 7 and Linux with another NTFS "Data" partition accessible from both operating systems. I've also set up partitions for two separate Linux installs, and a shared 4GB swap for them.
This is a quick guide on how to have Cowsay (or Tuxsay, etc.) with fortunes upon opening the terminal.
I have it set up using fortune's "wisdom" quotes. They're not difficult to create; install the "fortune-mod" package (along with "fortunes" and "cowsay"); use the strfile tool on a formatted text like "strfile vocab-fortune vocab-fortune.dat" and put it in fortune's directory, e.g. /usr/share/fortune or /usr/share/games/fortunes/ on Debians.