How to transfer my music files to my iPhone?

I plugged in my iPhone into my computer and I don't know how to put all of my mp3 files onto it, and yes, I have downloaded the latest iTunes. Anyone got some answers?

Make sure all the songs are in your iTunes library. Then on the left hand column click on your iPhone and then in the top tabs click on Music, and check "sync music".

First, I suggest organizing all mp3 files into folders by Artist and then putting those folders into your My Music folder on your computer. Then, simply drag all of the files into an open iTunes window and they should begin to be converted to AAC format and added to iTunes. Then, just plug in your iPhone and drag and drop your music from your library onto your iPhone using iTunes. Hope that works.

You can sync all the MP3 files via iTunes. If you have no iTunes installed, you'd better download it on the Apple official website at http://www.apple.com/.../download/