can I transfer music from dell computer to i phone 5

Yes. Add it to iTunes and sync.

Download iTunes: http://www.apple.com/itunes/download/?cid=wwa-us-kwg-music-itu

Adding music and other content to iTunes

iOS: Syncing your data with iTunes

You want to know how to transfer music from computer to iPhone. I think via iTunes is the most easier one.

Download iTunes > Add music > Connect your iPhone > Click in iTunes on your iPhone > Tab music > Check music you want > Sync.

Hope it works.