How do you put music on your MP3

I've not purchased music in very long time. I listen to Pandora (free music).
I've recently taken up running (my first 5k in August). I have an MP3 player now and I'd like to add new music to it for my runs and my workouts. I have never purchased music online before. Is there an inexpensive way to add music to your MP3?

My experience so far has been 99 cents a song on itunes.

I don't use an MP3 player, but I've copied most of my own cd's to my computer. I just pop the cd into the computer and rip it. I use Window's Media Player and rip the songs as MP3 files. I would guess you could then transfer them to your MP3 player.

You can copy music from cd to it easily. Just copy it to your My Music folder on your C drive, then plug in the mp3 player and copy it to there.

We use media monkey to do it. So far its been the easiest and fastest we have 2 sony walkmans and and ipod and it works well for both.

Hubby has ripped our music collection to the computer and we use media monkey to listen to it.