What is the best process for onboarding virtual employees? Do you treat them differently than employees who work on location?

Great question, if possible an initial week at headquarters or wherever those with whom they work with most is ideal. Strive to make the process consistent with that used in on-boarding any employee. Keeping virtual employees engaged and feeling like an integral part of the team can be challenging, so making them feel like they are an integral part of the team out of the box is critical. You should also encourage constant communication and the use of video in meetings using Skype and other tools to keep you virtual employees energized and engaged. I look forward to the thoughts of others who have or are virtual employees. I happen to fall into both categories.

With ever greater options about how/where/when people work, HR processes need be designed and operated to function consistently and, as much as feasible, seamlessly, in all contexts and places. Thus, the objective should be to make not only onboarding but all employee interactions common and congruent

we had BD folks who worked out of their homes and flew them in 2 or 3 times per year so they "stay connected"; to onboard, yes onsite is recommended and is critical to their assimilation into the organization. in the meantime I found this timely research that explains some of the practices regarding same topic. Provides specific best practices and validates some of suggestions already raised in this thread. http://www.businessresultsthroughpeople.org/associations/12672/files/Virtual%20Study%20Final%20Version%20March%2014%202012.pdf. Hope this helps.

We have our mobile employees 'come home' once every quarter and stay on-location for a week or so. During this time, they get updates on products, undergo training, contribute to new initiatives, share ideas and most importantly become a part of the camaraderie. And many of them have mentioned that even working from home can feel onerous and disengaging if done for too long. When they are remote, we usually video conference to keep them connected.

Regarding your question about 'what is the best process' - It really depends on what the current situation is and what you are looking to change.