The music in my iTunes library does not appear on my iPod after it syncs

*I had a ton of music that was already on my iPod but not in my library (I must have deleted the songs from the library). Yesterday when I opened iTunes I was prompted/asked to update it (as always it seems like), so I did, and it wiped out everything on my iPod.

*I then added music (610 songs) to my iTunes library and synced it, but my iPod still showed "no content" (I tried doing this several times)
I'm not sure if this is a conflicting factor, but none of my songs were purchased through the iTunes store, they were all either given to me from someone or downloaded elsewhere.

PS: These issues might be super easy to solve but I've never been good with using iTunes, but if you can help I'd appreciate it. Thanks!
iPod touch, iOS 6


*****Side question: I just joined this site and it automatically had a picture of me...is this site linked to another site that might have my photo stored? How do I remove it? *****