This is just a simple PostScript hack that I threw together when I needed some paper for my kindergartener to practice her printing on. It has lines on it similar to what I remember from when I was a kid, with the two solid lines that define the top and bottom, and then a dashed line in between them to help guage the middle height.
If you are comfortable dealing with PostScript, grab the source, and uncomment the line at the top that defines the orientation and the number of lines per page that you want. Since many people don't have the tools installed to handle PostScript (or the inclination to edit PostScript), I've generated the equivalent PDF files for the three setups that are included in the comments.