Many households--or even individuals--face the challenge of trying to manage multiple iPods, iPads, or iPhones one just one computer. This poses a number of challenges, including keeping each person's music and apps separate, to say nothing of different levels of content restriction or the potential for messing up each other's preferences.
There are a number of ways, using the tools built into iTunes and your operating system, to make managing multiple iPods, iPads, and iPhones on one computer easier. These four methods are listed from easiest/least troublesome to maintain to the least precise.
Creating a different user account for each person using the computer essentially creates a completely new, independent space in the computer for each person. Doing that, each person has their own username/password, can install whatever programs they like, and can choose their own preferences--all without impacting anyone else on the computer.
Since each user account is its own space, that means each user has their own iTunes library and sync settings for their iOS device. Easy to understand, (relatively) easy to set up, and easy to maintain--it's a good approach!
Using multiple iTunes libraries is a bit like having the separate spaces that the individual user account approach gives you, except in this case, the only thing that's separate is the iTunes library.
With this method, each person who uses the computer has their own iTunes library and sync settings. This way, you won't get music, apps, or movies mixed across iTunes libraries (unless you want to) and won't end up with someone else's content on your iPod by mistake.
The downsides of this approach are that parental controls on content apply to all iTunes libraries (with user accounts, they're different for each account) and that each user's space is not as cleanly separate. Still, this is a good option that's easy to set up.
If you're not concerned about mixing the music, movies, apps, and other content that each person using the computer puts into iTunes, using the iOS management screen is a solid option.
With this approach, you choose what content from each of the tabs in the management screen you want on your device. Other people using the computer do the same thing.
The downsides of this technique include that it only allows one setting for parental control of content and it can be imprecise (for instance, you might only want some music from an artist, but if someone else adds more of that artist's music, it could end up on your iPod).
So, even though it's messy, this is a very easy way to manage multiple iPods.
Want to make sure you get just the music you want on your iPod? Syncing a playlist of the music you want, and nothing else, is one way to do it. This technique is as simple as creating the playlist and updating the settings of each device to transfer just that playlist.
Downsides of this approach include that everything each person adds to the iTunes library is mixed together, the same content restrictions for all users, and the possibility that your playlist could be accidentally deleted and you'd have to re-create it.
If you don't want to try any of the other methods here, this will work. I'd recommend giving the others a shot first, though--they're cleaner and more effective.