I like to spend a week of school teaching kids how to use Google. Every year it changes so much. For example, this year I had to explain how Google uses Apps instead of websites for its services.
I start off by showing a video about the history of Google. This gives a perspective of the company that gives them a context as to why Google is so important to learn. Each year, it changes. Here is the one I used this year. https://www.youtube.com/watch?v=Quk88piD8PM
Next, I make sure they all have Google accounts. You can set them up for kids, but mostly, they will already have one. The account lets students access all parts of Google. Eventually, Google Classroom will help with this step, but it's not ready yet. https://classroom.google.com/signup
Then, depending on your class, walk though each of the different apps of Google. Change the apps you cover based off of your audience and course content. Just casually introduce each app and have them try it out. In my IT class, I like to cover them in this order:
I hate advertising for a company in my classroom, but I feel that the academic value of these apps outweigh my concerns. Make sure you talk about privacy online and how that when you use Google products, you need to protect your identity.
In the end, you'll have students who are comfortable using these apps, and you'll be able to use them to better manage your classroom.