Most Cisco Layer 2 devices do not support Netflow. Netflow is a more Layer 3 data collection. Also rather than the switch it's better to gather Netflow at the primary Layer 3 interfaces that traffic from the switich has to pass thru.
Your Cisco 2960 switches will have an option to set up a SPAN port. With SPAN ports you can choose to monitor ports or VLANs and you can download a free tool at this link which makes it easy to set them up.
Once you have your SPAN port setup you can use nProbe to convert the packet data to flow data. More on setting up nProbe at this link
There is another option of using an application like LANGuardian to connect to the SPAN port and then view the output via Orion. You can see an example of this here
Hope this helps
To configure Cisco 2960S switch , you can follow the easy steps below:
1. Connect the hosts to the switch and configure them
2. Connect the router to the switch and configure the router.
3. Configure the switch.
4. Configure the management interface on VLAN 1.
5. Verify the configuration of the switch.
6. Verify connectivity using ping and Telnet.
7. Determine which MAC addresses that the switch has learned.
8. Configure basic port security.
9. Connect a different PC to the secure switch port.
10. Reactivate the port.
11. Set speed and duplex options for the ports.
12. Exit the switch.