There are several ways you can configure OS X to have quick access to extended and special characters.
Topher KesslerMacFixIt Editor
Topher, an avid Mac user for the past 15 years, has been a contributing author to MacFixIt since the spring of 2008. One of his passions is troubleshooting Mac problems and making the best use of Macs and Apple hardware at home and in the workplace.
The OS X character palette is a convenient option for accessing multiple unicode symbols that are part of modern font collections. Not only can you use fun items like emoticons, but you can also enhance writing with scientific and mathematical symbols, foreign script characters, symbols, and even Braille.
Having these characters in the character palette makes managing them far easier than prior approaches in which unique symbol and dingbat fonts had to be used.
If you would like to use the OS X character viewer, it can be accessed in a few different ways:
The Edit menu
The most straightforward way to access the character palette is to use the Edit menu in OS X. This menu will be available in most applications, especially those that have input options for text, and at the bottom of this menu will be a "Special Characters..." entry that will bring up the character palette when clicked.
The Input menu
A second option for the character palette is to use the OS X input menu. This menu is primarily used for switching keyboard layouts for different languages, but can also be used to access both the keyboard layout viewer and the character palette. Since most OS installations are used in one region only this menu is off by default, but can be enabled by going to the Language & Text (or International) system preferences, selecting the Input Sources tab, and checking the box next to "Show Input menu in menu bar." Next be sure to check the options to include the keyboard and character viewers in the menu, and you should then be able to access both from the new input menu in the right of the menu bar.
In addition to using the menus for accessing the character palette, you can use hot keys to quickly bring it to the front. The default hot key for accessing the Character palette is Option-Command-T, but in some applications this hot key is not bound, requiring you access the Edit menu and select "Special Characters." This inconsistency is a bit inconvenient, but you can overcome it by manually reassigning this same hot key sequence (or another one of your choosing) to the Special Characters command.
To do this, open the Keyboard system preferences and choose the Keyboard Shortcuts tab. Then select the All Applications category and click the plus button to add a new shortcut. In the drop-down window that appears, ensure All Applications is selected and then type "Special Characters..." in the Menu Title field (note that the three dots are separate periods and not a single ellipsis character). Next put your cursor in the Keyboard Shortcut field and press Option-Command-T to assign this sequence to the hot key.
With this done, you should now be able to access the character viewer in most applications by pressing this hot-key sequence.