Taking screenshots is much easier in OSX than it ever has been before. All you need is the patience to make a few clicks or just a few fingers.
The most obvious way to take a screenshot in OSX is to use the Grab utility (/Applications/Utilities)
From here you can go up to the “Capture” menu and pick Selection, Window, Screen, Timed Screen. Selection will present you with a cursor to rubber-band a portion of the screen to capture. Window will take up one specific window that you choose. Screen will capture your whole screen (all 1920×1080 pixels of it if you’re working on a huge monitor…or more. The size will depend on you screen resolution.) Timed Screen will capture the whole screen 10 seconds after you hit the “Start Timer” Button.
Taking a screen shot from Grab won’t automatically save the resulting image. After taking a shot, you’ll be presented with a window containing the image. From here you have the option to save the image as a TIFF document.
But there’s an even quicker way to get basic screenshots. All you need to do is learn some universal key commands (universal meaning that it doesn’t matter what app you’re in – they’ll just work).
Command+Shift+3 is the default key command for a full screen grab. Command+Shift+4 is the default key command for grabbing a selected area (a cross-hair will come up for you to define what you want). You can go a step further with the selected area command by hitting the spacebar when the cross-hair appears, turning it into a camera. With the camera you can click on a window to get a capture of just that window; you’ll see each window become highlighted as you roll the camera over it.
By default your screen grabs will be saved to the desktop as “Picture 1” and so forth (add “ctrl” to the key commands and you’ll copy the image to the clipboard). They’ll be saved as PNG files, which should be good for most uses, but if you’d like to have higher quality for printing you may want to consider grabbing a utility like TinkerTool to change the output to TIFF and use Photoshop or another image editor to set the DPI to 300 (without resampling). Whether there’s really much of a benefit when saving TIFF instead of PNG, I’m not sure, but there are also options for saving in other graphic formats too.
Where do you find these things? Look no further than your own System Preferences!
From here you can customize your shortcuts to your liking. As you can see from my screenshot I have a shortcut conflict…maybe I should fix that.