DenW: once you've got your music into iTunes, you can create a new playlist (click the plus button bottom-left and give it a name), and then just drag any songs you want into that playlist.
Then goto edit->preferences->advanced->burning, and make sure the disc format is clicked on 'audio CD' if that's what you want. you'll only need to check this once.
Then go into your playlist and see that you songs are all there -- it'll say at the bottom how long they last for. a 700MB CDR will give you about 80minutes. Then click the burn button top-right.