It's true. A lot of plants for sale at pet stores are semi-aquatic. The rule of thumb I use for plants is RESEARCH FIRST, BUY SECOND. (It's the same rule I use for buying fish.)
Low light plants that work well for beginners:
If I were you, I would start out with some Java Fern, Java Moss and Anubias. Each of these needs to be attached to something else though. They don't do well with their rhizome (fern and anubias) under the substrate.
Another good plant is Amazon Sword. These can grow quite large, but that will take a good amount of time before you have to worry about it under low light. These are also sold in varying sizes, so you can decide how much you are willing to spend and buy the size that fits your budget. It will grow, but you need to be patient. It won't get humungous though under low light, but it will get to a good size. Mine have been growing for about 6 months and have tripled in size, but they started off very small, so they are only about 8 inches tall now.
Then you can go with Cryptocorynes, Echonodorus.
Courtesy of lijdma06:
Crypts small - c. parva
Crypts mid-sized - lutea, lucens, wendtii (all three colors red, green, brown)
Crypts large - retrospiralis, spiralis, balansae
And then there is the simplest plant to grow of all... anacharis or elodea. These things will grow no matter what you do. In low light, you might see it melt back a bit (same for most stem plants) but once it gets used to the light present they will grow. My leaves are much smaller than the leaves that I had on it when I bought it, because of the lack of light, but they are now VERY quick growing. I have to trim it back every two weeks or so. If I don't it would probably grow straight out of my tank! It's fun, because I put it in front of my filter outflow, and they sway in the current and add different movement to the tank than the darting around of the fish.
You are going to want to sift through this link for a BUNCH of useful information on all things plants...
including a thread on what Plants are for aquaria and which are not.