Place the seeds on in a moist paper towel. Put it all in a tupperware or a closed plastic bag. I have the tupperware in room temperature on the windowsills. This may seldom be the "right" place for the seeds, but it works. Remember that some seeds - like apple seeds - needs a hibernation period in cold temperature.
The sprouts don't grow in the same speed. Some are ready for soil after two to four weeks, other takes two to three months.. When the seeds seem ready, they go into the soil.
Some of my experiences with growing trees so far:
- Listen to advice from more experiened people.
- DO NOT listen to advice from more experiened people. Some "advices" are simply just lies.*
- The larger pot, the faster the tree grows.
- If the pot is transparent, it shouldnt stand in direct sunlight.
- It is ok if you dont have drainage for excess water as long as you are careful and don't water too much at the time.
* The weirdest lie I heard was about apple trees; It was said that apple trees naturally reproduces by grafting. In other words; a branch jumps off one tree, climbs up another tree and attatches to it; there are now three trees.
* Both tangerines and clementines may have seeds, even if only one of them is supposed to have it.