Whether you plan to upgrade as soon as you receive your install DVD on Friday or are planning to wait a few weeks or months, this post will detail the minimal steps you should take in preparation for upgrading your Mac to Snow Leopard.

Step 1 – Check for application updates/Snow Leopard compliance

Start with your most regularly used, mission critical applications, and make sure that they are up to date. More importantly make sure they are ready and compliant for running in Snow Leopard. If you are running applications that are not Snow Leopard compliant, you might want to wait on the upgrade until the developers release a Snow Leopard compliant version.

Step 2 – Purge

If you are like me, I NEVER take time to purge my Mac. Ever since Leopard was installed and all downloads went to the downloads folder instead of the desktop I haven’t purged a single thing. I’m certain that at least for me, 90% of the contents in my downloads folder can be trashed. While your at it, go through your applications folder and do the same thing. I probably have at least 100 trial versions of applications that I need to trash. Chances are that you do too. Don’t forget to empty trash after you finish purging.

Step 3 – Verify/Repair Disk and Verify/Repair Disk Permissions

When you are installing or upgrading an operating system, it’s always a good practice to make sure that the Disk onto which you’ll be installing or upgrading is in tip top shape. Apple has an application called Disk Utility that you can use to make a quick diagnosis of your hard drive’s condition. This application can be found in the Applications > Utilities folder. When you launch Disk Utility you’ll want to select your internal hard drive on which your current operating system is installed from the left hand sidebar and then click on the Verify Disk button which can be found toward the bottom right hand side of the application interface. Upon completion of the Verify Disk process you’ll receive a short synopsis of what the process found when it ran. If all is well, the final message will be listed in Green text. If there is a problem with your Disk, the final message will be listed in Red. If you get a Red message, your first course of action should be to manually initiate a Time Machine backup. Your second course of action should be to return to the Disk Utility application and click on the Repair Disk button located just beneath the Verify Disk button. Apple’s Disk Utility application is capable of making minor Disk repairs. If after running the Repair Disk process you still receive a Red final message, you should call AppleCare or make a trip to the Genius Bar and let them take a look.

After running the Verify Disk and/or Repair Disk processes, you’ll then want to run the Verify Disk Permissions process by clicking the Verify Disk Permissions button. If you’ve owned your Mac for any length of time, it’s quite possible that there may be some permissions that need to be repaired. If after running Verify Permissions the Disk Utility application lists permissions that need to be repaired, simply click the Repair Disk Permissions button just below the Verify Disk Permissions button. The repair process should take a few minutes and then you should get a message indicating which Permissions were repaired.

Step 4 – BACKUP!!!!

At a minimum you should manually run a Time Machine backup before inserting your Snow Leopard install DVD. I also recommend that you download Carbon Copy Cloner and create a bootable clone of your existing Macintosh Hard Drive. You’ll of course need a spare Hard Drive of some sort on which you’ll create the clone. After you’ve created the clone you’ll want to boot from the cloned copy to verify that it works. Once you’ve booted and verified that the clone works, you should be about ready to move ahead with the Snow Leopard upgrade.

Step 5 – Enjoy Snow Leopard and leave us some comments about your experience

As always, we’d like to hear about how your upgrade experience went. Did you have any problems? Are there any big exciting features that are surprises? Did any big exciting features not make the final release? Leave us some comments.