I didn't know I could do that on a Mac?!?
This document will show you how to use a few really useful (and some little-known) features of Mac OS X.
Spotlight is Apple's built-in "search everywhere" tool. Spotlight searches not only for the names of files, but inside those files as well. For example, say you can't remember where you saved a Microsoft Office document OR what you named it, but you know it contains the word "elephants". Use Spotlight to search for the word "elephants", and Spotlight will find it.
To use Spotlight, click on the magnifying glass icon at the top-right of your screen and start typing! The list of found items will appear as you type.
Did you also know that you can also invoke the Spotlight search window by typing Command+Space Bar?

Now that I found it, where is it?
Once the list of found items appears, just click on any item to open it. If you want to know where the file is wihout opening it, use the following method depending on the version of the Mac OS you're using:
Did you also know that hovering your cursor over an item and typing Command+Return will open the enclosing folder of that item in the Finder?

Power Searching
If you know the type of file you're looking for (e.g: pdf or an image), you can narrow down your searches in Spotlight by using Kind keywords. To describe the kind of file in the search, enter your search term in Spotlight followed by "kind:keyword" replacing "keyword" with one of the many file types that Spotlight recognizes. Some keywords you can use for searching include:

Exposé is a tool that helps you find and manage your open document and folder windows, even when your screen is cluttered. By default, the following keys are set to work with Exposé:
NOTE: Hold down the fn key + the keys indicated below
F9: Shows all open windows
F10: Shows all open windows in the front-most application
F11: Temporarily hides all open windows to reveal the desktop
Did you also know that you can activate Exposé by moving your cursor to the corners of your screen? Go to System Preferences-->Exposé & Spaces and select the corner and Exposé function using the Active Screen Corners pull-down menus.

Proxy Icons
"Proxy" icons are the little icons that appear at the top of document and Finder windows, and they're not just for show. Holding down the Command key and clicking on one of these icons will reveal the file or folder's location. The Proxy icon can also be used in the same way you would use the icon in the Finder: click and hold on the icon until it is highlighted – then drag it onto the desktop to move it, hold down the Option key to copy it or Command+Option to make an Alias of it (like a shortcut on a PC).
Did you also know you can use the Proxy icon trick in conjunction with Exposé to easily attach an open file to an email? This trick works best if one of your screen corners is set to Show All Windows. Create a new message in FirstClass, then switch to the open file you want to attach. Click and hold on the document's Proxy Icon and drag it to the corner that triggers all windows to show. Find your FirstClass message window and drag the icon back over that window. When the message window returns to its normal size, drop the icon under the "Subject" line and it will automatically be attached.

The "Services" Menu
The "Services" menu is listed under every application's menu and gives that program features from a different application. For example, try selecting some text on a web page while using Safari and then access the Services menu. You'll see that you're able to: instantly create an email from the selected text (Apple Mail only), create a Sticky Note or TextEdit document, search for the select text in Google or have the computer speak the selected words. Although the "Services" menu is available in every application, not every function is supported.
Did you also know that the selections in the "Services" menu may increase if you install other software? Some programs that add additional "Services" include TextExpander, TextWrangler, NetNewsWire, DEVONnote and countless others.

Screen Zooming
Screen zooming allows you to temporarily zoom in on part of the screen using the scroll wheel on your mouse or your track pad. This may be particularly useful during a presentation or if you're just having trouble seeing something. To enable this feature, go to System Preferences-->Trackpad (or Mouse) and check the box enabling "Zoom while holding Control". The Control key can be changed to the Command or Option key, if desired. To zoom on a laptop, be sure to enable "use two fingers to scroll" under the "Trackpad" settings. Then hold the "ctrl" key and use two fingers to swipe up and down on your trackpad.
Did you also know you can zoom in and out in Word documents without affecting the whole screen? Just hold down Command+ctrl while scrolling.

Dictionary Integration
Apple includes the New Oxford English Dictionary on every Mac in the form of the "Dictionary" application. But did you know that the dictionary is actually integrated into the Safari browser? Open Safari and place your cursor over any word on a web page, then press Command+ctrl+D. A small window will pop up showing the definition of that word. If you keep the Command+ctrl+D keys held down, you can move the cursor around the page to continuously pull up the definitions of all the words you move over. You can view the thesaurus entry for a word by clicking at the bottom of the window on "Dictionary" and selecting "Thesaurus". Clicking the "More.." button launches the main Dictionary program. This trick works in other Apple branded "Cocoa" applications as well, including TextEdit and the iLife programs.
Did you also know many of these same programs also include a "text-completion" feature? Try typing the word "rain" in a TextEdit document or in the Dictionary Widget, then click the "Option"+"Esc" key to see what happens...

Text Clippings
Say you're on a web page or in an email and there's a bit of text that you'd like to keep handy. You could copy and paste the text into another file or use the Services menu described earlier to save the text into a Sticky note, but did you know that you could also highlight the text and drag it to the desktop? Doing so creates what's called a text clipping, a small file you can access any time simply by double clicking. It's not editable, but you can only view it or copy its contents to paste into another program.

Customizing the Finder – Step 1
The default toolbar in a Finder window has buttons that let you change how the contents of the window are displayed as well as let you navigate backward and forward through opened folders. Did you know that if you right-click on an empty space in the toolbar, you'll bring up a contextual menu that will allow you to customize those buttons (e.g: add text to the buttons or make the buttons smaller) as well as delete or add new buttons?

Customizing the Finder – Step 2
If you choose to customize the toolbar, the window shown here appears. You can add items to the toolbar by dragging buttons from this window onto your toolbar. Drag items off the toolbar to remove them. Particularly helpful buttons are the "Path" button, which shows the folder location, and the "Delete" button, which will send any highlighted item in that Finder window to the trash.
Did you also know that you can add an application to a Finder window toolbar? Drag an application into the toolbar window and when the + symbol appears, let go. You now have one-click access to that program from every window.

For more great tips...
...visit: http://osxdaily.com/category/tips-tricks/