To induce fruiting and start growing your mushrooms they will need Oxygen (o2) and light. A lighting cycle of 12 hours on 12 hours off is the most common but mushrooms will tend to grow with even less light.
Mushrooms do not produce chlorophyll like plants do, so they need less light. most mushrooms will grow with natural light and natural daylight hours.
Do not leave your mushroom grow bag anywhere where they will receive direct sunlight, as this will cause them stress.
You can control your light cycle indoors by using a timer and cool white lamp, between 6000-7000 kelvins. (LED or Fluorescent bulbs are recommended)