Onboarding is different for individual contributors than it is for team leaders. In some ways it's easier. In some ways it's more complicated. The biggest difference has to do with the nature of the team.
My first job out of college was a sales representative role for Lever Brothers. My boss told me that his job was harder than mine because he had to manage five people. But he was wrong. He had five people that he could tell what to do. For me to get anything done, I had to influence 100 different people over whom I had no power (other than my charm and good looks – which for some unexplained reason seem to have been more powerful then than they are now).
The basics of onboarding are the same for leaders and individual contributors: get a head start, manage the message, build the team. It's building the team that plays out differently. Both leaders and individual contributors build teams by inspiring and enabling others. Individual contributors need to rely even more heavily on influencing skills across the five building blocks of a high performing team:
Team leaders should probably have a bias to co-creating a strategic imperative in a workshop of all the key players together in the same room at the same time.
Individual contributors will likely do better with a consultative approach, getting input from each of their key peers one at a time.
Team leaders should have their direct reports fold into the leaders' management process.
Individual contributors should fold their milestones into key peers' management processes.
Team leaders should focus on early wins that give the team confidence in itself.
Individual contributors should create early wins that give their peers confidence in the contributor.
A team leader's role sort is about getting the right people in the right roles with the right support.
An individual contributor's role sort is about choosing which people to go to for help and support.
While all great communicators do more influencing than directing, a team leader can direct sometimes.
An individual's communication is all about influencing.
Net, individual contributors should follow the prescriptions of The New Leader's 100-Day Action Plan when it comes to getting a head start and managing their message. When it comes to the team building pieces, individual contributors should apply them to the team they influence internally and externally instead of the team they directly manage.