I'm not that fond of using them for seedlings. They tend to dry out too quickly, requiring watering several times a day if kept under enough light. They can also stay excessively saturated for too long when totally wet, which can lead to damping off. I'd recommend starting the seeds in a seedling mix and small containers, then transplanting outside. But that's just me.

If you decide to use them, make sure you squeeze some of the excess water out of them after that initial soaking so that they won't stay too wet and possible smother your seeds. It's also not a bad idea to cut the netting off of the pellets when you think the roots are about to pop out the sides. When you start seeing roots protruding from the sides, you'll need to get them into some kind of container, or the ground as soon as possible. The roots won't survive for very long outside of the pellet and in direct contact with air/light.