Installing applications on Mac OS X is really easy compared to other devices. However, the approach taken can be confusing at first for many users. There are generally three basic steps when installing a piece of software; Acquire, Un-package, Install. In addition to the instructions presented here, software publishers usually give additional notes with their software that will help you more about the installation of their products.
Many new Macs don’t include an optical drive, so you can’t use CDs and DVDs. You could spend extra to buy a drive, but this Tip on making disk images could save you from that expense. Here’s how to make disk images from physical installation discs.
How to install a font, such as the free Gentium, on Mac OS X.
Double click a .pkg installer file to install the software it contains. After installation, delete the .pkg file.
How to install .tgz compressed software on a Mac.
How to install software from a .dmg (disk image) file.