[1MasterNinja1]

First you'll need to find the BPM.

http://www.mixmeister.com/bpmanalyzer/bpmanalyzer.asp

Once you found the song BPM then get into Stepmania and change the BPM, then go to Song Options and change the rate to 0.6, now that the song is slower it will be easier to find where the notes will go. And you can also go to Song Options and put on assist tick and see if the notes are on sync with the song.

Hope this helps.

EDIT: Also you can change the offset of the song if it is needed, in some cases it makes the song better. Also be sure the patterns in the song are fun to play, you can always try playing a song by a very good simfile artist and pay attention to how the notes were placed.