Barnature,
Plants are great. There are a few benefits - they will use nitrates in your tank, creating a healthier environment with less maintenance (although if you start getting into a high tech planted setup, there will be a LOT more maintenance). The tank will not be any harder to clean - really not much different than cleaning a tank with plastic plants. Plus, live plants look A LOT better (IMO).
As far as care for the plant, it really depends on what you want to get. Plants range from species that require almost 0 care, to plants that will require daily attention and a lot of money to keep the tank up and running at its best.
BEFORE YOU BUY ANY PLANTS: Check out
www.plantgeek.net. They have a section that details plants that are commonly sold as aquatic plants, but they are not suitable for growth in an aquarium under the water. No stores are immune from selling these types of plants (including, and especially big chain stores like Petsmart) so know what you want before you buy. It will save you a lot of hassle and frustration later as you try to figure out why your plant is dying and rotting and not growing.
The most important aspect to started a live planted tank is going to be your lighting. Most stock aquarium hoods that come with aquarium setups are inadequate for growing most, if not all, plants. If you let us know what type of lighting (flourscent, compact flourscent, t-5, mh, incandescent, etc) that you have, and what wattage the light is, that will be a good start. Also important when considering lighting is color spectrum and color temperature.
There are many options of plants that will not require much care beyond providing proper lighting. You can skip fertilizers and CO2 addition addition with these low light plants. These plant options would be,
Anubias, java fern, java moss, some crypts, anacharis, hornwort, and a few others. That site I referenced you to above also has a very inclusive list of low light plants so you can look at pics and decide what you want from there.
Let us know if you have any questions -- there are a lot of people on this forum that will help you get started.