WiFi Hotspot is only possible two ways (that I know of):
1) Root and run either a Gingerbread ROM for native hotspot, run ICS Sense with a third part app such as Barnacle, or run ICS AOSP (AOKP) with native hotspot.
2) Subscribe to Verizon's (way overpriced?) WiFi Hotspot feature and gain access to this feature natively without Root.
If you choose to Root and run ICS Sense, you will likely not be able to use native hotspot as it requires a compatible kernel and we currently do not ahve one. To gain one would require an official release or some willing to heavily modify the current leaked ICS Sense kernel, which would require a lot more know how and time than most people I know have.
Be careful how you approach tethering as it is against the TOU for Verizon without paying. There was a story about a person who had a suit thrown out because they had a tiered data plan and the court decided that since that person was paying for a specific amount of data each month, then they could use it however they saw fit. However, unlimited plans are not included in the finding and could still violate the TOU.
Kratos