I always like going back to the good old basics from Biology class, so many years ago.
Take out the paper towels, place the seeds between the wet towel and let it sit for a few days until you begin to see some root growth. As for the light or dark question, I'm not sure it matters then since it's sitting in a paper towel anyway. The seed isn't going to get any light when it's in the towel.
I also like to put the towel into a plastic bag so that it stays good and moist and protected from the outside world.
Once you have some root growth, then it's time to put it into the growing medium you've chosen.
Basics if you want to watch the seed germinate.
However, if you want it to grow in a way that maximizes its genetic potential.....if you want to get more females, if you want a plant that is healthier in every way.....
DON"T USE THE PAPER TOWEL METHOD.
For those who care:
1.)Look up Gravitropism
2.)Look up and learn what feeds a seedling the first part of its life
3.)Look at the effects light has on roots, especially young, tender roots.
4.)Look at what stress does to a plant, especially a seedling.
If you don't care, and are going to just do it anyways.....don't bother. Smoke a bowl, germinate the seeds any way you want and have a great time. That's perfectly OK and like I said, anyone who grows Cannabis has my respect and admiration.
However, for those who want to maximize their results and grow the BEST product.....don't use the paper towel method.
Traditions are fine. But if we always base what we do on tradition, we make no progress.
If you are striving for excellence, ditch the paper towel.
The first 3 days of a seedling's life are the most critical part of its whole growth cycle.