Q: How does one transfer the data from a pc laptop to my new iMac?

When you initially turn on your Mac for the first time it starts up Setup Assistant, part of setup assistant is migrating data from your PC (or older Mac if you have one) to the new machine. If you already got your iMac and skipped that then you missed the best opportunity. However you can still migrate if you did using Migration Assistant. Please read Apple's About MS Windows Migration Assistant & Pondini's Lion Setup Assistant tips.

Another method is doing it manually, you will find more information in Apple's Switch 101 url.