Network Driver From Scrach

Hi All, I want to first understand and then write a network driver for simple Ethernet device (actually instead of inbuilt network driver i want to run my network driver). Actually the new driver should have PF_RING enable/support and Net filter usage. Although we can copy the driver too but i want to understand some driver and write my own so that i get clear understanding about network driver. Now can you please help me how should i proceed? First should i see how the packet flows in the kernel or how should i go and please provide some good links to study. Thanks