Hi Chundra,
I would recommend using MQX to get up and going very quickly. It includes a fully feature Ethernet stack with all source code included, and has projects specific for the TWR-K60F120M. You can download it from here: http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MQX
Make sure to read the following documents:
C:\Freescale\Freescale_MQX_4_1\doc\MQX_Getting_Started.pdf (and make sure to read section 9.13 for jumper configurations for the TWR-K60F120M and TWR-SER)
C:\Freescale\Freescale_MQX_4_1\doc\MQX_Release_Notes.pdf
And then based on the IDE you want to use (I'd suggest Kinetis Design Studio to get started with if you don't already have one picked out) read the appropriate documentation in C:\Freescale\Freescale_MQX_4_1\doc\tools. It'll have instructions for compiling the MQX libraries.
You can find several example Ethernet programs in C:\Freescale\Freescale_MQX_4_1\rtcs\examples
Finally you may also want to look at the TWR-K60F120M Quick Start Demo package. It was built for an older version of MQX so the project/instructions are slightly outdated, but the instructions included in the package still have useful information for updating OSJTAG and other board information: http://cache.freescale.com/files/32bit/software/app_software/code_examples/TWR-K60F120M_QSD.zip
-Anthony