Basic care tips:
Flowering plants and those with coloured leaves need more light than do leafy plants. For rooms with very low light levels, consider installing
Overwatering is the most common mistake beginners make. Allow plants to get almost dry, but not wilted, then water until liquid flows from drainage holes (drainage holes in all pots are a must). Test for moisture by sticking a finger (to first knuckle) into soil every five days. If it feels dry, it's time to water.
Daytime temperatures of 18 to 23°C with a 3 to 5°C drop at night are ideal. Avoid placing plants near heating ducts or in drafty areas. To increase humidity, add a layer of marbles or stones to the plant saucer, fill base with water and place pot on top. The stones will suspend plant above water and prevent root rot.
A little goes a long way. Avoid feeding during winter dormancy. In February, start adding houseplant fertilizer, following the manufacturer's instructions.
Wipe dust off leaves to keep clean and allow plant to breathe better.
Pests and disease
Examine tops and undersides of leaves. If you see bugs, try spritzing them away with water and a drop of ordinary dish soap. Or use commercial insecticidal soap. If a plant can't be saved, throw it away and discard the soil, so the problem won't spread to other plants.
This website has the results from a NASA study listing the best houseplants for purifying the air:
Houseplants for Dummies by Larry Hodgson, IDG Books Worldwide, softcover, 384 pages, $24.99.