To find the version number of Mac software you click on the software's name from the menu bar (top left) and then About software's name from the menu. This will open a small window with details about the software.
To determine the version number of any Mac OS X software click on the name of the software (for example iTunes) in the menu bar (top left) and select About iTunes. This will open a window with details about the software. If the software is not running you can right click on the software's icon and then select Get Info from the menu. This will open an Info window with details of the software.
When installing a new version of iTunes only the iTunes software is updated your library is not touched.
If you are running iOS 5, you can update to iOS 6 wirelessly from Settings>General>Software Update. If you are running an older version of iOS, you have to plug you iDevice into an iTunes-authorized computer and download and install the update software from there. You should be prompted there is new software available the moment iTunes recognizes your device.
New iTunes software can be installed to update the previous version. Only the iTunes software is updated the iTunes library with your music/videos etc. is not affected by the update.
A new version of iTunes only updates the iTunes software and does not touch your music/movies library.
If you are updating the iTunes software to the latest version your music library will not be affected.
Yes. However if you download iTunes again you will just be updating it to the newest version. No music will be lost. You can use the Check For Updates option in the iTunes menu which will give you the latest version. Or check Software Update from the Apple menu which will check all your default software for newer versions.
Updates to the iTunes software only affect the iTunes application and does not touch your music library.
The iTunes software is free and can be downloaded from the Apple website (See links below).
If you download the latest version of iTunes, it will automatically download the latest version of quicktime. Also, when you download itunes, you can also choose to download apple software update for your computer. when you open apple software update, it searches for new updates in iTunes, quicktime and safari.
iPod software is updated by plugging the iPod into the computer and using Apple iTunes software to upgrade.
Picture messaging is available on every model of the iPhone, including the 3G. However, this feature is only available if your iPhone software is running on version 3.0 or later. You can check your software version by going to Settings > General > About...and then scrolling down to "Version". If this says you have a version older than 3.0 (such as 2.x), then you need to update. All you have to do is plug your iPhone into your computer and start iTunes. Once iTunes recognizes your phone, click your phone's name on the side bar and you should see a message informing you that a newer version of software is available. Allow iTunes to perform the update and, after your iPhone reboots, picture messaging will be available.