I'd recommend checking the datasheet for the flash chip (I'm not familiar with the DE2 board).
Atleast on the DE0 board, the flash is a lot more straight forward to access (you don't have to worry about column/row signals). It's access times are slower though (70/90ns) and from what I gathered you have to read/write sectors in one go.
I'm using this to debug my project (it's signal processing) by downloading data onto the flash using the control panel, processing it on the FPGA, then downloading the results back through the control panel for analysis. I haven't yet written any code (trying to get the EDA tools working first!) but will post back here if/when I do.