As for your question on seeds, it depends where you order from, such as the vendors in amsterdam where its perfectly legal. And as for environment, the plants will do best with an ambient temperature of around 28 Celsius. You need to consider a few factors when growin cannabis. Water, light, earth, air, co2, and nutrients. Plants werent meant to grow indoors which means its up to you to replicate their outdoor environment as best as you can. If you do it well your plants will grow and thrive. Hope this helped a little bit, check the Newbie Thread, and it'll answer most of your questions. Happy growin'
Cheers, Sergeant Stoner