I have done this several times. No pictures. The time required for some visible proof that the seed is developing depends on many factors. In my opinion, the most important element is how ripe the fruit was when you removed the pit. Avacados are a bit unusual in that they continue to ripen even after harvesting. That process includes seed maturity. I learned to allow an avacado to become overripe ...even mushy...before removing the seed. I've had these seeds take less than a week to several weeks. Just keep it in a warm, sunny location and remember to water occasionally. If you water TOO frequently, though, the seed can rot.

Put in a damp paper towel in an open zip-lock, leave in a drawer, or in the kitchen, not in direct light. Check it every few days to make sure that the paper towel has a little moisture (not wet!). As soon as the seed begins to split, pot it into a well-draining potting mix, half buried. Josh

You can plant the pit so that the roots are down and the shoot is up. They WILL bend that way if you were to plant it in the 'normal' position, but there is NO need for you to do so. Roots will always exhibit positive geotropism (growing down in response to gravity), while shoots will develop under negative geotropism (against gravity). Plant the seed in the direction it has already begun and give that poor plant some LIGHT!!! ;-)

I did not have time to read all the posts but can contribute. I have successfully raised and given away several avocado trees using the toothpick method but have found a better way. Seal the cleaned seed in a ziplock bag with a wet paper towel. Lay it in a place where you can see it daily. It takes some time to sprout. When the root emerges, put it in a pot with the root end down. Water it once per week. That is all. It will flourish. I do have a question though. When can the seed be removed? I had a tree about two feet tall that I put outside. A squirrel ate the seed that was still attached and severed the trunk of the tree which suddenly died. Since I now have three seedlings in my office, I need help before I put them outside.