I speak both Windows and Mac :
For day to day maintenance:
ONYX :
<i>Ensure you use the correct OS Version </i>
Very good for the small general maintenance that makes a difference for a Mac
Software Update: I know, however if really does make a difference
Console for review of error logs: Found in the Applications/utilies folder or use Spotlight (Command + Spacebar)
AppCleaner (think REVVO for Mac)
Omnidisksweeper : for review of Harddrive space usage
And Learn this !
How to reset Mac users password: (Many users <b>never</i> use their password as auto-login for Mac is very prevalent
Hold Apple+S when booting to enter single user mode
#sh /etc/rc
#passwd yourusername
#reboot
These are <b> very </b> useful:
During boot if you press:
C You start from a bootable CD such as your install DVD in the drive.
D Perform an Apple Hard ware test if you have your install DVD in the drive.
N Boot from a network compatible server. Only useful if you have the server.
T Start up in Target Disk mode. You can usually connect to another Mac through Firewire and do lots of funky things. Gone out of fashion and not used as much.
Option Start up using the Start Up Manager. Here you can pick which drive you want to boot from. Known to people who use BootCamp. You can also boot from a CD which is the same as press C.
Option then N Similar to the item above, except you get given the choice of booting from a network disk.
Option + N Boot from the first network boot image.
Command + V Boot up in Verbose mode, where you see lots of text whizzing by which is not a lot of use to you. I have written about this command here. It will also show Verbose output on shut down.
Command + S Single User Mode. This is where you can run a lot of high level tasks as a single user. Probably not for newbies. You could probably break your computer very quickly in Single User mode. More about it here.
Shift Start up in safe mode. Very useful if you have a problem and need an environment where you don’t want unnecessary things loaded. A good bet if you get Kernel panics during boot.
Option + Command + P + R Reset NVRAM. Although you will probably never need to reset this RAM it contents some useful stuff that can become corrupted. If you are having really bad problems this may be a good lead to follow. More information on Apple’s website.
Hold Eject or F12 or Mouse Eject anything that is in the disk drive.
I wasn't going to touch this, but some things really need to be elaborated on and I'm just going to do it.
Software Update: I know, however if really does make a difference
I agree, but its far from perfect and also can break things. Also software update can choke on a certain update and bottleneck the entire process. Best thing to do if you suspect an update has broken something is manually download and install the most
recent combined update. If software update won't install updates, its really nothing to be too terribly alarmed with. It usually happens when a bunch of updates are being installed all at once. You can do the manual download of the combo installer or the quick and dirty way is by unchecking some of the updates in the bunch and do them one by one, which usually sorts out the update that id bottle-necking the process. This applies to all versions of OSX 10.7.4 on down. Now with 10.8, software update steers you right onto the app store. So I'm assuming a manual update installation with Mountain Lion is going to be handled by option clicking the update through the app store and selecting "show package contents" and then going from there. But of course, this option will only be available once the download has already been installed at least once through the app store. But we shall see?
T Start up in Target Disk mode. You can usually connect to another Mac through Firewire and do lots of funky things. Gone out of fashion and not used as much.
Far from out of fashion and actually that statement couldn't be further from the truth. Anyone remember back in late 08 when Apple had discontinued firewire in some models? Well, unlike Apple, they reconsidered (thank goodness) and now firewire is still available on all recent models but the Macbook Air. Without firewire, there is no target disk mode. A machine in target disk mode connected to another Mac acts as an external hard drive or another mounted volume. Furthermore a machine in target disk mode can be used as an external optical drive connected to another Mac with a fubar optical. I regularly use target disk mode to slave to my bench machines to perform backups, create disk images of volumes, and clone to and from other machines all the time through disk utility (something else extremely useful included in OSX). Furthermore, Firewire transfer speeds are (as of the last 6-7 years) 800Mbps. Better yet, firewire runs pretty much independent of the processor which make speeds more consistent (unlike usb 2.0). If/when thunderbolt really takes off and the implementation of usb 3.0 on the most recent Mac models, firewire may become more unnecessary and irrelevant. But for now its still extremely handy (unless every single time you'd like to slave a drive, you'd like to pull the drive).
Command + V Boot up in Verbose mode, where you see lots of text whizzing by which is not a lot of use to you. I have written about this command here. It will also show Verbose output on shut down.
Verbose mode is more than text whizzing by and is useful. If a Mac is hanging on boot, it's a very handy troubleshooting tool. The text whizzing by can show you what may be causing the hangup as the entire boot process is logged in real time and visible as it happens. Maybe this was already intended to be elaborated on by OP but his links aren't working?
Shift Start up in safe mode. Very useful if you have a problem and need an environment where you don’t want unnecessary things loaded. A good bet if you get Kernel panics during boot.
I don't know so much safe boot fixing kernel panics, as it may temporarily provide a booting environment where it's making a kernel panic less likely. Kernel panics can be caused by just about anything. However, safe boot is extremely handy and even a very good maintenance routine in itself. Safe boot is especially useful if you have a Mac with really hard to pinpoint issues and I found as a consistent fix for the blue screen at login occurrence that can be common with OSX. It's widely believed that safe boot fixes more issues than Apple even acknowledges besides what is already
documented by Apple. In short it disables many unnecessary kexts (kernel extensions) and fonts, clears many hidden caches all while forcing fsck (UNIX abrevation for file system check) at boot. Never underestimate the power of safe boot.
Option + Command + P + R Reset NVRAM. Although you will probably never need to reset this RAM it contents some useful stuff that can become corrupted. If you are having really bad problems this may be a good lead to follow. More information on Apple’s website.
Does way more than clear only NVRAM or video RAM. Also known as zapping PRAM or PRAM reset. Basically it clears the contents of video RAM and a whole slew of other settings. Also good for shutting off things that will run constantly at startup like verbose mode. Should be a first step in troubleshooting just about any hardware issue (especially no video, or general video issues, or even sound issues) or peripheral issue. To do a proper PRAM reset, follow the key sequence mentioned by (most importantly) holding the key combination for at least 3 chimes (or the gong sound to Mac noobs). A good description of the contents of PRAM is
here.
One very important thing not even mentioned is the
SMC (System Management Controller) reset. Known and similar to the PMU (Power Management Unit) reset on PowerPC Macs. SMC reset is a first try hardware resolution routine for issues like power, charging and fans, along with a variety of other things. Should be used with caution or only used when really necessary as too many resets may even crash the SMC chip. So it's necessary sometimes, but once is plenty. Unlike the universal key combination for a PRAM reset, SMC reset procedure depends on what Mac is sitting in front of you and some machines can have a couple different ways for performing the SMC reset.