SOPC builder problem for Embedded System

I am very new to Altera SOPC builder

I am building an Embedded system in DE2 board. The hardware part sends buffer memory status to the software part (via usb blaster) to indicate how much memory resources the system has already used and software generates appropriate arbitration based on the memory status. Memory status is stored in a RAM before sending it to software part and I have declared memory altera megawizard Plugin Manager. The software part is developed on Nios II IDE.

Now my questions are:

1) What are the component I need to declare in SOPC builder in order to complete my system?

2)How does the SOPC component reads the memory content which is build by megawizard? Do I need to store these data into external memory that comes with the DE2 board in order to make the data transferable to software part?

3) Where do I store the arbitration data coming from software part? Can I just store these data into external memories (that comes with DE2) and hardware component will be able to read these data directly?

I would really appreciate any help from you.