Shift, just after logging in, to prevent Finder windows from opening and startup items from opening, for this boot.
Start up in single user mode, which is a minimal BSD Unix environment. You can run /sbin/fsck -fy from the CLI, which will force-correct any disk problems. If you get a message that "FILE SYSTEM WAS MODIFIED" this means fsck found and repaired problems. Run it again until no error messages show: i.e.: ** The volume (name_of_volume) appears to be OK **. Exit single user mode by typing reboot.
Force a "Verbose" startup. Show Unix console messages during startup, and see what is going on behind the scenes as your Mac starts.
Display the Open Firmware screen.
Zap the Parameter RAM (PRAM). Start holding the keys prior to the grey screen after boot, hold them through the reset and an automatic reboot, through the second startup tone. Resets settings such as: display / video settings such as refresh rate, screen resolution, number of colors, startup volume, speaker volume, recent kernel panic info if any, DVD region setting. Be sure to go into System Preferences afterward and set the clock and timezone, and speaker volume.
Start from external drive (or CD).
Show the icons of all startup disks, for selection.
Start the Mac in "safe mode" and thereby force a check of the startup volume, and run only necessary kernel extensions. This might be used, for example, to get out of a failed upgrade which is looping the setup assistant. Press shift right as you hear the startup sound, and release shift when you see the grey Apple logo and spinning progress indicator. Give this process time. Leave safe mode by rebooting.
Starts up in Mac OS X (if OS 9 is also present on the same disk).
Enter FireWire Target Disk mode, which allows another Mac to access said Mac in Target Disk mode as if it were an external hard drive. Cable sold separately.
Start up from network server using the default NetBoot image.
Start up from the first partition.
Start up from a bootable CD or DVD in the internal drive. You might do this when upgrading, or when you need to run something like Disk Utility from the original Mac OS X DVD. Once you boot to the OS X DVD, you can choose Disk Utility from the Installer menu, and then choose "First Aid". As an aside, you can use "DasBoot" utility to create bootable discs.
Delete the word to the left of the cursor.
|del, or fn-delete on a laptop|
Delete the text to the right of the cursor, or "forward delete". Marked with a right-facing arrow with an x on full sized keyboards.
Delete the text to the left of the cursor.
|option-Right and Left Arrow Keys (shift)|
Move the cursor to the beginning or end of this or the next word to the right or left. Add shift to select.
|Cmd-Arrow Keys (shift)|
Move the cursor to the beginning and end of a line (left, right arrow keys) or the top or bottom of an area of text (up, down arrow keys). Add shift to select.
|esc while typing|
Autocomplete a word being typed by pressing esc.
Paste text and match it to the surrounding text. Same as "Paste Special, Plain Text" in Windows.
|Cmd-X, C, or V|
Press Cmd with X to cut, C to copy, and V to insert text. Think this way to remember these. X looks like scissors, or "no good", C stands for "copy" and V is like the proofreader's mark for insert.