If you can read a book in a room on a foggy day without the aid of artificial light, there is plenty of natural light to suit most plants. Create more light in a room by using mirrors, painting walls white or supplementing with gro-lights. Most house plants do not care for bright direct sunlight, especially from south or west windows. Direct sunlight from a warm window will burn the foliage of most plants. Bright diffused light is best.
Most house plants can, however, tolerate light from north and east windows.
The rule of thumb when watering house plants is to water only when the top inch of soil becomes dry. Give the plants a good soaking, enough so that water pours from drainage holes. Don't water again until soil surface becomes dry. This watering technique helps to leach fertilizer salts out of the soil. Salt build-up is often responsible for browning leaf tips on many plants, especially palms and spider plants.