I am making cake for 300 which is the largest quantity I have ever had to make. Does anyone have any recommendations for the best way to do this? I was thinking several sheet cakes, but not sure what size sheet cake pans to do! Oh, by the way it is for a graduation reception.

If you do double layer 12x18's they feed 100. Also, you could do two layer 14" squares which feed 98.

A 12x18x4 sheet cake will yield 108 servings 1x2x4.
That's 2 cakes stacked together w/filling between them.