Another aspect of becoming a lead/manager that takes some time to wrap one's head around is what your role is now. You are no longer judged based on your own actions, but rather the collective actions of your team. With all of the time you will likely spend developing people, attending meetings, reviewing work, etc., your direct contribution to the collective output of the team will be low. This is more and more true, the greater the number of reports you have.
The role of a lead is fundamentally different from that of an individual contributor. A lead is tasked with maximizing the output of his or her work group. More often than not, this means that the lead takes a back seat when it comes to "real work." It is more important that you spend your time growing, unblocking, and dealing with bureaucracy than it is that you fix a bug or implement some feature.
Writing software takes a lot of concentration. It takes unbroken time to just sit and work. As a lead, your day is usually broken up. It is hard to get that time to concentrate. When you get it, it often comes at the expense of other things. You won't have the same opportunities you once had. Instead, your day will be working with others to solve their problems. You will be helping people develop themselves. You will be helping to prioritize the work. You paying more attention to the project as a whole than to particular features. This is all good work, but it is very different from your previous life as an individual contributor.
This becomes really apparent when it comes time for reviews. At Microsoft we have a review system where we are judged based on the goals we set for ourselves and our ability to achieve those goals. When you are an individual contributor, your review is easy. You just list off everything you did during the previous year. I wrote this. I tested that. I drove this iniative. When you become a lead, your review changes. When you sit down to write your first review as a lead, you'll notice that your individual accomplishments were not what they once were. That's okay though, you are no longer responsible for just "I." You are now responsible for "We." You are judged by, and it is okay to claim credit for, the work of your team. We wrote this. We tested that. One of my reports drove this iniative. The first time you write a review like that, it feels like cheating. After all, you didn't do that work. Your role has changed. That work took place because you facilitated it. You kept people focused and unblocked so they could give 100% of their effort. Welcome to your new job.