Depends on the format you use for your songs really, a typical AAC or MP3 is probabaly around 3 to 5 MB. If you consider that a 60GB ipod can hold 15000 AAC format songs you can compare that to the available space you have.
My 20GB Scrollwheel iPod has 2056 songs (MP3 at 192kps) and is using 12.9 GB. Thats 6450Kb average per song... so a 60GB iPod should hold 9562.7 average length songs at 192kps... if my math is right.