Keeping plants alive indoors can prove next to impossible to some, but it really isn't all that hard to do. Plants need light, water, support, nutrients, and an adequate air supply.
Like anything in this world, excessive amounts of any one thing is often a bad thing, even if that substance is necessary for survival. Just because you think your plant might want more of something, doesn't mean you are doing your plant any good. The fact of the matter is, unless you know what you are doing, you may very well be killing it. Plants can't scream in pain like the rest of us....
Step 1: Try to figure out what your plant is called
Each plant will have a common name, and a Latin name. For the most part, knowing the common name should allow you to find the growing requirements of your plant. Latin names are often better, as they are universal. But no one is forcing you to learn the names of your plants, and certainly not the Latin names.
These names will only help you find extra information on how to grow each specific plant, and how to correct any problems that may occur.