The more difficult part of naming piano notes is naming the black keys.
Though it may be harder, if you can name the white keys, then you can easily name the black ones. If you need help naming the white keys check out my explanation on Naming the White Piano Notes To name any of the black keys all you do is find a white key that is directly next to the black key.
You then determine if it is a sharp or flat. (Check out my lesson on Sharps and Flats) If it is to the right of the white key it will be sharp, if it is to the left then it will be flat.
For example, if you are wanting to find the name of the note labeled in the image, you find the white notes that are around it which are G and A.
You then name it based on its relation to those white notes.
So, the black notes relation to the A is to the left which makes it flat so it will be an Ab. It is also to the right of the G which makes it a G#.
How can a note have more than one name? It all depends on what key you are in.
If you are in the key of Eb then that note will be called an Ab. If it is in the key of B however, it is called a G#.
Whichever key you are in determines the name of the note.
This may seem confusing for you right now but, if you look at my lesson on Key Signatures it will help you.
Below is an image with all of the names of the white and black notes for reference.