Cacran,
The problem with a green house is that it can get awful hot on a sunny day - a north facing window in unheated room is ideal.
Caroline,
Putting sprouted seed in the dark will not stop the sprouting, it will mean that the sprouts will grow but be longer, thiner and paler than they would be in the light.
Mr Romans should not use poly bags (email him and let him know you're not happy) - a lot of seed from WCF Phoenix (where he gets his seed from) was sprouted this year, we were not happy and have told them so
Phil