where did you get the pattern
I didn't use a pattern, I just looked at some different tutorials around the internet and then charted out my letters on graph paper. You can, however, use any alphabet pattern for cross stitch and it'll work perfectly as a filet chart. There are some filet crochet free alphabets around on the internet too.
Pieknits - One site that helped me wrap my head around filet crochet was the tutorial at http://www.smartcrochet.com/tutorial.shtml. I also found these Youtube links helpful, just in terms of visually seeing someone else do it. http://www.youtube.com/watch?v=rrberusTznc# and http://www.youtube.com/user/CrochetMD#play/uploads
Hope that helps!