The first thing I do when I purchase an Amaryllis bulb kit is toss aside the plastic pot and "soil" that comes with it. Those plastic pots that come in the kit are usually very flimsy and don't have any drainage holes so they get put aside for later use. What passes for "soil" in the Amaryllis bulb kits is usually a disk of coco coir that looks more like a coaster for your coffee table.
Why I don't use the "soil" and pot from the kit.
Plastic pots have their place in the indoor garden but housing an Amaryllis bulb is not one of them. The pots are so lightweight that when your Amaryllis produces a flower scape and leaves it will topple over and you'll spend most of your day picking up the Amaryllis or finding ways to weigh it down. Avoid the hassle and just use a heavy pot; terracotta, ceramic or metallic- it doesn't matter as long as it has drainage holes and is heavy. If you have no other choice and can only use the plastic pot punch several good sized holes in the bottom of the pot with a screw driver (or something similar) for drainage. A good sized pot for an Amaryllis is 7 inches deep and two inches wider than the bulb you're planting.
The coir disk that comes with the pot is a fantastic potting medium for something like a terrarium but it isn't suited for Amaryllids. It takes a good 45 minutes to an hour to become rehydrated sitting in water. If it dries out again with a bulb growing in it you're bound to over water your Amaryllis bulb trying to get the "soil" rehydrated. Then there is the potential of creating a breeding ground for white flies and gnats who will make themselves at home in that "soil." Avoid these problems and use your favorite houseplant soil instead.
Once you've chosen the right pot (with drainage holes) and the right soil for your bulb the next step is to pot it. Fill half of the pot with the potting soil and position your bulb in the center of the pot and then fill the soil up to the "shoulders" of the bulb. When you've finished the top 1/2 to 2/3 of the bulb should be exposed above the soil line and there should be about one inch from the top of the soil line to the rim of the pot.
1/2... 2/3...one inch...huh?
I know, I know. I'm not good with numbers either so hopefully the image above makes a good visual aid. See how the whole bulb is not submerged in soil? Notice how the soil in the potted Amaryllis above doesn't go to the top of the pot? The reason the bulbs are planted so "high" in the pot is so to avoid watering into the neck of the bulb and rotting it and the higher the bulb is in a pot the more room there is below for the roots. That's my main problem with this Amaryllis vase I posted about before, there isn't enough room in the "vase" for the large roots the bulb will eventually produce. If the image doesn't show up in that link try this link to the photo in my web album. The reason for the extra inch of space between the soil level and top of the pot is because the soil will eventually settle after I water it and so I can top dress it with pebbles or stones and lessen the chances that those annoying little flies will find a home in the soil.
After you've potted your Amaryllis bulb give it a good drink of lukewarm water and set the pot in a warm and bright window. Water sparingly for the next few weeks and only as needed as the bulb works on producing roots, the flower scape and leaves. The bulb in the picture above already has a scape (flower stalk) trying to emerge, your bulb may produce leaves first but that doesn't mean there is anything wrong with your bulb. Try not to move your bulb during the first few weeks until it has grown enough roots to anchor itself into the soil.
I've set up a new blog at www.AmaryllisBulbs.org that will be devoted to my Amaryllids. I think Amaryllids have gone past the "fad" stage for me and it is time to delve deeper and experiment with propagation techniques and hybridizing now that I have a few bulbs in my collection. If you're curious I am using this very same blogging platform for that blog just with a custom domain and if anyone is interested in turning their garden blog into a dot com, net, org...I'd be more than happy to make an entry detailing my experiences and thoughts on going through the process with Blogger.
Here's a video I made showing you how to pot an Amaryllis Bulb.
Here's a video showing you how to pollinate an Amaryllis flower and what the seeds look like.