To sync the folder, click on an iOS device's icon in the iTunes source list (your device must be connected via USB or using Wi-Fi syncing). Now go to the Music tab, check Sync Music, then choose Selected Playlists, Artists, Albums and Genres. Select the folder you just made, or select any or all of the playlists it contains. Only those items will sync. Each user can have their own folder, and sync that to their device.
Q: I have an iTunes library with about 35GB of music, and I have an 80GB iPod classic and a 16GB iPod touch. I want the whole library synced with the classic, but only playlists and podcasts synched to the touch. How do you accomplish this?
As in the answer to the previous question, you can choose to only sync selected playlists, artists, albums or genres to each iOS device. For your iPod touch, go to the Music tab as described above and choose the playlists you want.
Then, go to the Playlists section and check the ones you want to sync. A shortcut: If you want to select them all, press and hold the Command key and click on any of their checkboxes; they will all be checked. To uncheck them all, do the same thing again.
Q: I upgraded my home network to run Lion server, and connected my external drive with my iTunes music files to the server. Home Sharing works fine; however how do I now sync my iOS devices with the music on the server?
If you have iOS devices that can sync via Wi-Fi--iPhones, iPads and iPod touches--you need to connect them to the server once and check the Sync With This devicename Over Wi-Fi setting on the Summary tab when the device is connected and selected. Make any changes you want, selecting what to sync, and you can then disconnect the device. Make sure you don't eject it from iTunes by clicking the arrow button next to the device.
Next, on each iOS device, when you want to sync it, go to Settings -> General -> iTunes Wi-Fi Sync and tap Sync Now.
This won't work with the iPod classic, nano or shuffle, though--you need to physically connect them to the server to be able to sync.
Q: When I sync over Wi-Fi, I always get a message on my iPad that a certain number of items could not be synced, without any information as to what they were. The message says that I should look in iTunes for further information. When I go to iTunes, there is no indication of what was not synced or why. Can you help me with this?
This is one of iTunes' more frustrating alerts, and it boggles my mind that Apple would use it this way. Hey, Apple, can you fix this? Please?