TIP: Check or uncheck all songs in a playlist
If you want to quickly check or uncheck all the songs in a playlist or album, hold down the Command key (Macs) or Control key (Windows) and click on any of the checkboxes in the list. Unchecking a box will uncheck all the boxes; checking a box will check all the boxes.
TIP: Removing a song from your iPod does not remove it from your computer
All the media content in your iTunes library is stored on your computer's hard drive. If you remove a song from your iPod, it will remain in your iTunes library on your computer. Deleting a song in your iTunes library will delete it from your hard drive.
TIP: Create a playlist from selected songs
You can quickly create a playlist of only selected songs from your Music library. Select multiple songs from your library (hold down the Command or Control key while selecting songs) that you want to be in your playlist, and then click on File >New Playlist from Selection. A new untitled playlist of the songs you selected will appear at the bottom of your Playlists on the left side of the iTunes window.
TIP: Create a Smart Playlist
The Smart Playlist feature allows you to create a playlist that iTunes will automatically build for you from music you already have in your iTunes library, based on criteria you set for it. To begin creating a Smart Playlist, go to File >New Smart Playlist.
This brings up the Smart Playlist dialog box, which lets create a set of rules used to select songs for the playlist. The first pop-up menu lets you specify artist, category, musical genre, composer, and other criteria. The second menu lets you further refine the search criterion specified in the first, such as "contains" or "does not contain." The third field lets you further refine the search. For example, if you wanted to create a playlist containing the songs of Simon & Garfunkel, you'd select "Artist" from the first menu, "Contains" for the second, and "Simon & Garfunkel" from the third.
You can create a Smart Playlist with multiple sets of rules by clicking on the "+" box on the right side of the dialog box. You can also limit the number of songs, match only checked items, and have iTunes update your lists whenever you add new music to your iTunes library by checking the "Live updating" box.
TIP: Use the Equalizer to change music playback settings
Just like on the iPhone and iPod touch, iTunes includes an Equalizer where you can adjust different sound frequencies to your own personal preference, or use one of the many preset frequencies such as Rock, Pop, Electronic, Bass Booster, etc. Go to View >Show Equalizer (make sure the "On" checkbox is checked, and click on the Equalizer field to select a preset setting).
Equalizer adjusts the sound to your preferred setting.
TIP: Use the iTunes Mini Player
If you are playing music in iTunes and don't want the iTunes window to take up your entire screen, you can switch to the Mini Player mode, which shrinks iTunes into a mini media player that only has the core playback functions (previous track, next track, play, and volume control). In Windows, go to Advanced >Switch to Mini Player (or CTRL+M). On Macs, click on the green plus button in the upper right-hand corner of the iTunes window.
You can shrink the iTunes window into a convenient Mini Player.
TIP: Quickly get more music from an artist
If you want to quickly get more music from a particular artist in your music library, highlight the song and click on the arrow link to the right of the artist or song title. This will open the artist's iTunes Store page, where you can find more music. Note that you must have an option under the iTunes Preferences menu (Preferences >General tab >Show links to the iTunes Store) activated for the links to appear.
TIP: Apply Ratings to songs
iTunes allows you to give songs in your library a rating of between zero and five stars. Once you have rated your songs, you can then sort them by rating or create Smart Playlists with only songs of a certain rating. To rate a song, you can select it and click in the Rating column or right-click (Macs: CTRL-click) on a song and select Rating.