I am so new to having a garden .. in fact everything I have ever touched dies on me!!! My question : what is deadheading? Is that where you break off the dead flowers at the end of their season. I have black eyed susans and some purple flower that I have no idea what it is. Also, if this is 'deadheading' (breaking off the dead flowers) do you take away the leaves of the black eyed susan also or just break away the stems from the flowers that are dead?

If all the blooms on the stalk are done blooming, cut the whole stalk down to the ground. That's what I do, not sure what everyone else does. It looks much neater.

deadheading is popping off the spent flowers, I usually just pull the flowers off after they start to look a little "tattered". Deadheading is good to do if you want the flower to continously keep blooming and not go to seed (the flower production will decline and the energy will go into seed production if you let the flower die on the plant). However, I'd leave a few flowerheads for seed, black eyed susans will freely reseed and spread into big beautiful masses if you want them to do that.