It less than 24 hours to go.. and here’s the basic list from MacFixit..
Topics covered include:
• Backing up your data
• Preparing your startup disk
• Other pre-update precautions:
– Make sure all devices are synchronized prior to updating
– Disconnect all external devices, update firmware
• Install options:
– Upgrade
– Archive and Install
– Erase and Install
• Upgrade applications to Leopard-ready versions, if they are available
• Disable plug-ins and other application add-ons (or upgrade them)
• Check for, and delete, corrupt .plist files
• Do not run DiskWarrior and other directory utilities after updating
Read it up in here