How do I place a 2nd iPod on my iTunes account so that....

Question

...neither iPod loses its particular apps, games, music, etc when it synchs? Yes, I know this is supposed to be simple, simple, simple. But it wasn't, wasn't, wasn't EVER with the 2nd iPod's predecessor.
Brief history: I have an iPod. Yay. All very fine and well. Synched it with my computer and it worked and we lived happily ever after -- until my 10-year-old an iPod last Christmas and I tried to create an account for it on the same computer, using Apple's directions. Hah! Upshot: The two iPods then lived happily never after together and much cursing rained from my mouth when "Method Three" resulted in the erasure of my own iPod's library at iTunes.
I managed to restore that using my own iPod -- though my library was renamed "Previous iTunes Libraries" and I never have managed to successfully rename it. It remains "Previous iTunes Libraries."
Meanwhile, that awful burp was enough to get the second iPod working and thereafter we never could get the thing to synch without destroying my own iPod's library -- even though it was recognized as a second iPod and there was a second account and everything. Consequently, we stopped synching the stupid thing which was OK since the 10-year-old could charge it without connecting to the computer and he was using it mostly for games and a few songs which we downloaded wirelessly.
Then his iPod screen cracked -- apparently, it's not the best idea to let them slide between sofa cushions and then sit on them. Luckily, its one-year protection plan was still active and we just got a brand-new replacement. Stupidly, I tried to synch the thing again last night in an attempt to download the games and history that he had so it could go on the new iPod. Sigh. You know: Big mistake. My own iPod's library is now full of swiss-cheese holes and I've lost things that I'd taken off my iPod so I guess they can't be replaced. I decided to forget trying to save his iPod's history and we're starting over, from scratch, with the new iPod. He'll have to get apps, etc, and start over again with his games, etc. And I pray to God that we can set up the iTunes account so it actually works this time. Please! Help! Me! Do! This!
I've been told that Method Two (second iPod is just a different playlist) is best but what about apps? If both iPods have, say, Angry Birds, does Method Two save two separate sets of Angry Birds, each with its own history? I figure my lost songs/apps are gone forever as is everything that was on his iPod even though it was purchased with my user ID and all that. I figure this is a bad, bad dream but I am hoping you will help me wake up from it into a nice, shiny, smoothly working iPod world.
Thanks for your time and I appreciate all help! The new iPod is not going to be used at all until I'm somewhat confident/hopeful that I can pull off this allegedly simple and easy operation.

Answer 1

9850,
you can do it by creating sub-folders within the folder that is selected to be synced.
e.g.  Folder "Photo" has been selected to be synced to your iPad.
Create two sub-folders e.g. "Family" and "Vacation" within "Photo" folder and put photos in both sub-folders instead of "Photo" folder.
Now sync your photos and in photo's tab, after you have selected "Photo" folder to be synced, make sure you select all Folders as example below:
Once completed you will find both folders "Family" and "Vacations" are in your iPad's album including Camera Roll.  e.g. below: