Best Practices before doing any Mac OS System Upgrade
Best practices before doing any Mac OS upgrade:
0) Read the info on compatibility with your software:
OS X: About incompatible software - http://support.apple.com/kb/HT3258?viewlocale=en_US
1) Always backup your data.
Make a good and complete backup with Time Machine and/or make a copy of your disk with Disk Utility.
2) Understand how to restore your backup (you did make that backup!) before you start.
How to back up and restore your files - http://support.apple.com/kb/HT1553
3) Make sure that all software updates have been completed before upgrading.
4) Repair the startup disk with Disk Utility before upgrading and after upgrading.
Download the latest OS X install application from the App Store or from Software@NCState and install.