Nios II and ADC -- Cyclone III Dev. Board

Sorry, I've only just started using Altera FPGAs, and so far things went fine with Verilog and without using Nios II.

I would now like to use a Nios II soft-processor for some signal processing applications (matched filtering, for example). I would like to read the incoming signal from the ADC.

I found a few examples on how to use the Nios II, but I did not find a single example, where an ADC or DAC were used. Where can I find such? How can I access the data that is coming from the DAC?

Is it best to write the data from the DAC into some memory (SRAM, DDR) and then access that memory from Nios II?

I'm a beginner with this and confused...

Any help is appreciated! thanks in advance.