House plants beautify your environment, purify air indoors, and create a naturalistic element to often sterile-looking office spaces. Because they grow and change, some people even view plants as companionable. They can be very easy to care for with a few tips to keep them healthy.
Be sure that your plants get light. Plants need light! Identify how much natural light is available (and needed) for plants, or whether it is possible to have an indoor grow light placed next to the plant. A window is an ideal place but make sure you have a saucer or tray underneath the plants to catch the drips from watering and condensation which often occurs at night on the leaves.
Water them as needed. Plants need water, but not too much nor too little. When you water, water it until you can see it come out of the bottom of the pot. Never put plants in pots that don't have at least one hole in the bottom! Be realistic about how much attention you have to give to your house plants, and plan accordingly. Larger plants in large pots need watering less often than plants in very small pots, which will dry out every couple of days. Cactus and succulents need less watering than thin-leaved or flowering plants (although when cactus produce flowers they need a bit more water than otherwise). Go to a reputable greenhouse and research different kinds of plants for their light, space and temperature needs and choose a plant that looks beautiful to you but is also suitable for your space and time available to care for it.
Watch out for plant pests. Sometimes plants attract pests - insects that eat the plant and cause it to lose vigor. Some plants are less susceptible to insects than others. Plants with thin leaves tend to get spider mites and whitefly, others get scale or mealy bugs. Learn how to identify these pests and how to treat them (usually a soil-drenching systemic insecticide will do the job, but not always, so it's important to learn about these things.) Mold and viruses can also affect plants as well, but they are less common. There is lots of information on the internet on how to treat these maladies.
Use a nice pot. A decorative pot or planter that coordinates with the furnishings can really enhance the beauty of the plant. It helps the plant a lot if the pot or planter is on a tray with about an inch of aquarium gravel in it. When you water the plant, the water goes into the saucer and evaporates around the plant, making the surrounding air a bit more humid. This is especially helpful to the plant in winter. Make sure the water doesn't touch the bottom of the pot, because if the pot ends up sitting in water, the plant's roots will rot and the plant can die. Place a trivet underneath the tray so that the tray doesn't sit directly on a wooden or painted surface. The moisture in the tray will cause condensation underneath it, and that can damage wood or painted surfaces. When you water, wipe up any spills pretty quickly.
Water the plant when the pot is noticeably lighter than it was when it was watered last. Again, different plants have different watering requirements. Some plants can go for a couple of days dry, others, especially flowering plants, need a shorter interval of dryness. Few plants, with the exception of aquarium plants and papyrus, like wet feet for more than a day! Finding the right balance of moist versus dry is the challenge of keeping happy and healthy houseplants.
Know what will work best for you. Some good houseplants: Floor plants: Dracaena marginata (dragon trees), ficus (both the large and small-leaved varieties), sanseveria (mother-in-law tongue), spathiphyllum (peace lily), umbrella plants. Avoid bird of paradise, bamboo, palm trees and ferns unless you can provide very good light and high additional humidity year-round. Different plants do well in different climates. Do your homework, and don't always trust florists or the folks at Home Depot, who are more interested in selling the plant than making sure it is healthy or happy in its new home. Window and table plants: kalanchoes, cane-stem begonias, African violets, orchids (moth orchids are fairly easy but only bloom once or twice a year; compliment them by surrounding them by attractive foliage plants). Philodendron (pothos or sweetheart plant), maranta (prayer plants), Syngonium podophyllum (arrowhead plant), crassula (jade plant), zamioculcas and Beaucarnea recurvata (ponytail palm). Try not to be tempted into bringing plants that normally grow outdoors all year indoors, such as fuchsias or wax begonias or even coleus. They don't do that well indoors after being outside all summer, and can be an unfortunate source of bugs that could invade other indoor plants you get. There are many different kinds of plants, and some people become avid collectors of one or several families of them. If you want to be even extra-specially conscientious, make sure the plants you purchase are greenhouse grown, and not wild-collected or endangered species. : )