I know, this is kinda cheesy, but seems to work - I'm just missing the right
criteria.

I have a column of data that continues to grow, so I need to sum the entire
thing just using C:C. However, the catch is, I want this sum total to be in
the same column, but at the top. This of course causes a circular ref error.

In column B is data that goes with the neighboring cell in column C. So, I
want to use =SUMIF(B:B, <not-sure-of-criteria ,C:C), but cannot find the
correct criteria to say that if B contains anything, then add the C data.

To avoid the circular reference, I just make sure that the B cell next to my
sum-formula cell in C is blank. :-)

I know this is probably easy, but I'm having troubles searching for the
right thing, so hence not finding my answer.