Supriyo,
You will need to install GPIB and VISA software. This is avaialable on your LabVIEW CD. You should also install MAX (Measurement and Automation Explorer.)
As you are new to LabVIEW, you can probably get some assistance from your local sales rep. I also suggest that you consider taking some courses, and get familiar with NI's support resources (such as this forum, and ni.com/ask.)
Once you have those elements installed you will be able to talk to your instrument. Be sure to open MAX and scan for GPIB instruments to test things out before moving back to LabVIEW.
-Mike Du'Lyea