Keyboard short cuts in MAC

Startup and Login

command+option+O+F	Invoke Open Firmware
command+option+P+R	Reset PRAM
T	Startup in FireWire Target Disk Mode
option	Invoke Startup Manager
command+S	Invoke single-user mode
command+V	Invoke verbose mode
C	Boot from CD/DVD
X	Boot into OS X (if you previously booted from OS 9 on the same volume)
shift (immediately at startup)	Safe boot
shift (after boot screen, until login screen)	Override auto-login
shift (after login screen)	Safe login
option+escape, then click on a user	Present name/password login dialog instead of list of users

System-wide

option+volume up/down/mute	Open Sound preferences
option+brightness up/down	Open Display preferences
command+space	Cycle through active keyboard layouts/scripts
F12	Eject CD/DVD drive (hold down for two seconds)
return or enter	Select default button in dialog (OK, Open, Save, etc.)
escape or command+.	Exit/cancel dialog
command+shift+Q	Log out
command+option+shift+Q	Log out without confirmation dialog
power button (laptops) or control+eject (desktops)	Bring up Restart/Sleep/Shut Down dialog
command+option+eject (desktops)	Sleep computer immediately
command+option+escape	Bring up Force Quit window
command+control+eject (desktops)	Restart immediately (chance to save changes in open documents)
command+option+control+eject (desktops) or command+option+control+power (laptops)	Shutdown immediately (chance to save changes in open documents)
command+control+power button	Force restart (no chance to save changes in open documents)
hold power button	Force shutdown (no chance to save changes in open documents)

Universal Access (must be enabled in Universal Access preferences) 

command+option+8	Toggle zoom (screen magnification) on/off
command+option+=	Zoom in
command+option+-	Zoom out
command+option+control+8	Toggle display inversion (white-on-black) on/off
shift (five times)	Toggle Sticky Keys on/off
option (five times)	Toggle Mouse Keys on/off

Full Keyboard Access

control+F1	Toggle Full Keyboard Access on/off
control+F2 (or control+M)	Focus keyboard control on menu bar
control+F3 (or control+D)	Focus keyboard control on Dock
control+F4 (or control+W)	Focus keyboard control on active Window or cycle to next window
control+F5 (or control+T)	Focus keyboard control on toolbar
control+F6 (or control+U)	Focus keyboard control on palette (utility window)
control+F7	In windows and dialogs, switch focus to text boxes/lists/controls
arrow keys	Navigate active item
return, enter, or spacebar	Select highlighted item
return or enter	Select default dialog control (OK, Yes, No, Save, Open, etc.)
escape	Cancel action, menu, or dialog

Finder: General 

command+J	Open View Options
command+shift+delete	Empty Trash (with confirmation dialog)
command+option+shift+delete	Empty Trash (without confirmation dialog)
command+F	Bring up Find dialog
command+K	Bring up Connect to Server dialog

Finder: Files and Folders 

command+shift+N	New Folder in active Finder window (including the Desktop)
arrow keys	Navigate items in active Finder window
tab/shift+tab	Select next/previous file or folder (alphabetically)
type name of file/folder	Select that file/folder
return	Edit file/folder name
command+O	Open selected item(s)
command+I	Open Get Info window for selected item(s)
command+option+I	Open File Inspector window
command+D	Duplicate selected item(s)
command+L	Create alias(es) for selected item(s)
command+R (for aliases)	Show target of selected alias ("reveal original")
command+T	Add selected item(s) to Favorites (creates alias in Favorites folder)
command+delete	Move selected item(s) to Trash
command+down arrow	Open item(s); add option key to close current folder
command+up arrow	Switch to enclosing folder (if no windows are open, opens new window to Home); add option key to close current folder
option+right arrow/left arrow (folders in list view)	Toggle disclosure triangle for selected folder(s) open/closed
command+option+right arrow/left arrow (folders in list view)	Toggle disclosure triangle for all folder(s) open/closed

Finder: Windows (Application shortcuts, listed below, also apply to the Finder)

command+N	New Finder window
command+1/2/3	View active window as Icons/List/Columns
control+tab or control+I (in list view)	Change column sorting; cycles columns left to right (add shift key to cycle right to left)
command+B	Show/hide window toolbar for active window
command+shift+C/H/I/A/F	Go to Computer / Home / iDisk / Applications / Favorites in active window (a new window will be opened if necessary)
command+shift+G	Bring up "Go to Folder" dialog in active window (a new window will be opened if necessary)
command+[ or command+]	Go back or forward in window view history
command+W	Close active Finder window
command+option+W	Close all Finder windows

Finder: Volumes/Media 

command+E

Eject volume/disc

Open/Save Dialog Shortcuts

tab	Switch between browser and text fields
arrow keys, page up/down	Navigate in browser
command+N	Create new folder in the current directory
command+D	Change directory to Desktop
command+shift+A	Change directory to /Applications
command+shift+C	Change directory to Computer view (list of volumes)
command+shift+F	Change directory to Favorites folder
command+shift+H	Change directory to Home folder
command+shift+I	Change directory to iDisk (mounts iDisk if necessary)

Dock (see Chapter 6)

command+option+D	Toggle Dock auto-hide on/off
command+tab	Cycle through active applications; each tab press while holding command changes the application once. Add the shift key to cycle backwards. As long as you keep the command key pressed, you can also quit or hide applications as you cycle through them.

Applications, including the Finder

command+H	Hide current application
command+option+H	Hide all other applications
command+M	Minimize active window to the Dock
command+option+M	Minimize all windows in active application to the Dock
command+`	Cycle through current application's windows (add the shift to cycle backwards)
command+,	Open application preferences dialog (not universal yet, but becoming more common)

Screenshot

(By default, screenshots are saved to the Desktop in PDF format; add the control key to any of the combinations below to copy the screenshot to the clipboard instead; you can then paste it into any graphics application -- such as OS X's Preview -- and save it in any format you prefer.)

command+shift+3	Full screenshot
command+shift+4	Crosshair to allow selection of screenshot area
command+shift+4, then spacebar	Camera to capture specific screen object

Text-related shortcuts in Cocoa applications 

Type bindkey <RETURN> in Terminal for complete list (in the list, ^ means the control key).

Source : homepage.mac.com

Delete option Mac

Mac will not delete the files with just delete of the button.

You have to click on "Command + Delete" to delete the files. These are moved to Trash folder. So you can restore them if needed. Empty the trash frequently if you dont need them any more.

There is no option to permanently delete the files in MAC with out moving to trash, like the "Shift + Delete" in windows. You need to have some automators installed if you want to have permanent delete option in MAC which I feel is not preferable.

Mac - Screen shot : Windows print screen alternative

IF you are looking for an alternative to print screen(windows) in MAC then just follow below simple easy steps....

Find below options to take a screen shot of your choice....

• Full Screen Shot - If you want to take the screen shot of the complete screen you have on screen  follow the below steps.              

                   Select keys  "Command + Shift + 3"  at once.
                   Release the keys, now a complete screen capture image of your screen will be available on your desktop. Rename it if needed.

• Selected Screen Shot - If you want to just take a selected part of the screen shot then follow below steps.

                  Select keys  "Command + Shift + 4"  at once.                   
                  Release the keys.
                  Now you will see the mouse cursor will change to + symbol.  Start at a point on the screen from where you need screen capture and release till where you need it.   You are done, a image will be available on your desktop with the selected portion captured.          

• Screen shot of a particular application - If you want to take a screen shot of a particular application follow below steps 

                  Select keys  "Command + Shift + 4"  at once.                   
                  Release the keys.
                  Press "Space" bar.
                  you will see a camera image on the screen. Just click it on which window you need the screen capture. You are done, an image is created on the desktop for you with the screen capture of the window.

In all the cases, keep your window on top/selected for which you are planning to take a Screen Capture. 
By default all the images will be saved on your desktop and will be given some name. You have move and rename as per your needs.