Where is the flaw in my growing skills?

So I purchased two legitimate syringes of p. cubensis + , I then went out and purchased organic brown rice flower, and organic vermiculite.

I then took a clean 1/2 pint canning jar and, using the erowid growers guide, i mixed up the substrate and put it into the jar. I then put the jar in a pot of water and boiled the water and let it sterilize for an hour in the water. Let the jar cool along with the water, and then once the jar was completely cooled I proceeded to inject them with the solution in the syringes. After this I placed the jar in the back of my closet where it stays pretty warm, above 72 degrees constantly. From there I let the jars cultivate. after a few days, spots of white mycelia began to grow.
After a few weeks the jar would be completely white. (HERE IS WHERE I THINK I MAKE MISTAKES) How long do the cakes need to stay in the jars before they are ready to be popped out into the fruiting jar...
Do the jars need light when cultivating?
I cant seem to get any mushrooms to grow. I dont understand what the problem is. I try to expose them to air but also keep the jar sealed so there is humidity. I put a damp paper towel at the bottom to help build up moistness. But the cakes seem to die, or something happens to them and they dry out.
I know its hard to tell just form this what could be wrong, but is there any obvious mistakes im making?

 

You need to make a fruiting chamber:

http://www.shroomery.org/10254/PF-TEK-Update-The-Shotgun-Terrarium

Simply keeping the mushrooms in the jars will not yield fruit.

 

http://www.shroomery.org/10256/PF-Tek-v2

I always let my jars go until the substrate pulls away from the edges and is completely covered with mycelium. should take about 2 weeks at 72dgs. If you are achieving these results you are ok at this point.

Now for my fruiting i use a large (maybe 12x12x24) rubbermaid storage container, its clear as well. At first i hooked a humidifier directly to this and opened it twice daily just to fan large drops off my cakes. I now just fill the bottom of the container with about 3 inches of damp perlite(way easier).

Sounds to me like your trying to grow your shrooms in jars? sounds bad, i recommend the above method. The humidity in whatever your growing them in needs to be visual, as close to 100% as possible. Mushrooms are like 90% water so this is important and i think its your problem. Make sure everything you use after the cakes come out of jars is superclean too. When your shrooms start to grow if you notice some that don't grow but just stay little pins eat them, they are the best!

Have fun bro!