The $ symbol is used to make the cell references absolute - if you had
a formula which referred to D3 and copied this down the column, it
would become D4, D5 etc, and if you copied it across the row it would
change to E3, F3 etc. Sometimes you do not want this to happen, so the
$ symbol in front of the row or column reference prevents it from
changing.

The ampersand is used to join text together and is known as the
concatenation operator - it does the same job as the CONCATENATE( )
function. In your example, the equals sign is being added to the
beginning of the contents of C38.

The SUMIF( ) function allows you to add values together if some
condition is met. In your formula, the values to be added are in the
range H3 to H28, and each cell of this range will be summed if the
contents of the corresponding cell in the range D3 to D28 is equal to
the contents of cell C38.

Hope this makes things a bit clearer for you - you can find more
details in Excel Help.

Pete