I am also new to Perl, but the way I see it is that the prefix tells me whether the result I am going to be playing with is a scalar or a list. Thus...

Something starting with $ is a scalar -- the parentheses or whatever after the identifier tell me that it comes from an array (or hash or whatever), but the value returned is a scalar nonetheless.

Similarly, if there is an @ preceding an identifier, the value I am playing with is a list -- it may be from an array, an array slice, or whathaveyou, but it is still going to be a list.

I'm sure I am oversimplifying, but it's a way of looking at things that works for me in the simple programs I have written so far.