How to transfer iPod music/video to iPhone library?

I'm really new to getting around iTunes. I only have a nano now and I know how to put songs on it and that's all. So, is there a way to transfer songs from my iPod to my iPhone? I've been poking around on there and I can't figure out how. A lot of music on my nano is not on my computer or iTunes. My old computer died and I had a lot of my music on my nano, thankfully.

Refer to this iMacsoft iPod to PC Transfer and learn how to transfer iPod music to iPhone step by step.
1. Connect iPod, iPhone to PC
Free download and run iMacsoft iPod to PC Transfer, you will see the iPod nano and iPhone list are displayed in the left panel. All info and library files (music, movie, books, ringtone, photo, playlist,etc.)of iPod nano and iPhone can be viewed fast and easily.

2. Transfer iPod music/video to iPhone
1)In the "iPod nano" list, click "Music" item and see all the music files on the right.
2)Select what you wanna transfer and check them totally, see illustration as below.
3)Drag all the checked music files towards iPhone device, when the screen shows the signal "+", drop the music files at once. You will see the iPod nano music to iPhone sync process. Several seconds later, the music files have saved into iPhone music library.
Tips: If you wanna transfer iPod videos to iPhone movie library, just click "Movie" item and check the movie you wanna transfer, drag them and drop down to the iPhone list. So iPod movies also can be easily transferred to iPhone.