Mac GURU 
Do you want to keep your Mac running smoothly with little chance of problems? Follow this advice and you will have far fewer problems-if any.
Set up a schedule
Daily and/or Weekly
a) Backup important folders/files. If nothing else, backup the System Folder, bookmarks, e-mail address book, and any important documents.
b) Check versiontracker or macupdate for updates to software you are using. Make sure they're compatible with the Mac OS you have installed before applying any updates.
Monthly
a) Run Disk First Aid & Norton Disk Doctor &/or TechTool Pro &/or Run DiskWarrior. Use Norton Utilities on IDE hard disks, use DiskWarrior on SCSI hard disks or if Norton cannot fix an IDE drive due to severe directory damage. Tech Tool Pro is another good repair utility for diagnosing hardware issues.
b) Rebuild the desktop.
c) Back up the entire hard drive and make a second backup to store off site.
d) Run your virus software.Use Virex or other products available such as Norton AntiVirus.
e) Defragment your hard disk with Norton Speed Disk (comes with Norton Utilities or Norton SystemWorks).
Every 6 months
a) Zap the PRAM
b) Reinstall/update the hard drive driver with Drive Setup. I do NOT rercommend the use of 3rd party drive formatting software unless you need to-as Mac OS system updates may not install and/or run well IF software drivers need to be updated AND the manufacturer of your 3rd party drivers does not come up with updated drivers.
c) Trash the 'Finder Preferences' in the 'Preferences' folder in the 'System Folder' on the hard drive. Then immediately restart and empty the trash. Now reset control panels that have defaulted such as 'Date & Time', 'General Controls', 'Memory', and 'Mouse'.
Yearly
a) Clean out the 'Preferences' folder for any applications you no longer use by trashing the related preference file(s). If you're not sure, then put the file(s) in the trash. Now restart the computer and test your applications to see that they run fine before emptying the trash.
b) Open the computer case and blow out the dust with a compressed air aerosol can.
c) Clean the mouse ball and rollers. Use Q-tips moistened with rubbing alcohol on the rollers. Never use sharp objects. Warm water and liquid soap for the ball is fine. Completely dry before reassembling.
d) Clean the keyboard with compressed air and a moist Q-tip and non-abrasive cloth.
e) Clean the monitor case and screen. Follow instructions in the monitor's manual. Never put liquid directly on the screen; use a moist non-abrasive cloth.
Hard drive diagnosis and repair utilities
Disk First Aid - free with your Mac OS installation.
Drive Setup - free with your Mac OS installation.
Norton Utilities/Norton Anti-Virus/Norton SystemWorks
DiskWarrior This is the BEST OS X repair utility bar none and what i recommend you buy!!!!!
Hard Drive defragmenting and optimizing utilities.
Norton Speed Disk (included in Norton Utilities or Norton SystemWorks)
Back up utilities
Also I am available to provide the services listed above on an onsite basis if preferred.