How to take downloaded music from PC and put it on iPhone 3gs?

Okay first, yes I have an ancient iPhone. I have downloaded a TON of music from YouTube MP3 converter thingy for free. Link: http://www.youtube-mp3.org/ and want to put it on my iPhone but everytime I connect it to my laptop it says my iPhone is camera. What do I do?

Plug it into your computer

Plug into your computer then transfer the song from your computer to your iPhone 3gs.

1. Download iTunes
2. Install iTunes
3. Open iTunes
4. Drag songs (or folders of songs) to the iTunes window
5. Now, connect your iPhone to the laptop