Look at the example below and see how B to C is a half-step
because the very next note up, white or black from B, is C.

If we start on C and move a half-step up it is actually
the black note immediately right of C.

So what should we call this note that is 1/2 step up from C?
We call it C sharp...read below and it will be explained!
Here is a picture of a sharp sign.

When you see this sign it means that the note immediately right
of this sign is to be played one half-step up.
The easiest way to remember this is to think that when you sit on
a sharp tack,
you go straight up - and so do "sharps".

A sharp sign is always immediately left of the note.

Here are the name of the sharp keys.

Below is "When The
Saints" using a sharp sign.