Getting started is simple
The first step in scaling agile is easy — well, relatively easy compared to later steps. Before you contemplate scaling, first make sure you can create a single effective agile team. At a minimum, to create a single effective agile team you must start by giving the team what it needs to be successful, then listen for their emerging needs, and fulfill those needs quickly. Given the right ingredients and the right support, accomplishing this first step is almost a given barring major organizational culture issues.
But it gets harder
Step 2 gets a bit more complicated. On the surface it's pretty straightforward. Simply repeat whatever you did to create that first effective agile team. Be prepared though. It might not be so easy the second time around. Here’s why:
To achieve the first effective agile team, most organizations do things like dedicate staffing to the team; establish a team room; allocate tools, equipment, environments, and so forth to that team's exclusive use... in other words, remove all of the impediments that might otherwise get it the team's way of being an effective agile team. Then, if anything was missed and the team discovers a new impediment, swoop in and get the impediment out of the team's way.