Where to begin.

There are a lot of types of organizations: government or public, bigs or smalls, SOHO, etc, and all of them has their own objectives. This heterogeneity of organizations makes that each one has their own motivation when establishing their Business Continuity program.
A key element used to be news: when a disruptive event, a natural disaster or a unexpected event occurs it could wake up some kind of awareness in directors that can say what about if it happens to me? Thereafter, the direction used to identify internally the business continuity manager, in order to carry out the program and, if there are enough budget, ask for external hep form consultants.

The next step is looking for a reference that  can show the better way to achieve the program. Both, BC guides and standards (GPG from BCI, ISO 22301, etc) and consultancy methodologies develop a inventory of business process, resources inventory, risk assessment, business impact analysis, ....

But what I' going to put forward is a different way to begin in Business Continuity, that, from my  personal experience, could be the best way. The main aspect of any initiative is the awareness so is the first thing we have to promote and this grant us the success in the others phases of the program. And, of course, the best way for awareness is with TEST. So, my recommendation: carry out a drill without a lot of preparedness but, of course, always with the complicity of direction.

An example that I have experienced in this way was a drill in an European organization  at which arrived a new director, who had been working in the military. He decided to conduit a drill based on a bomb in the main entrance of the building. Surprisingly, the results of the drill were better than expected, mainly because of the leadership of this director, but a lot of lesson could be learned and there were a lot of conclusions that were drawn and actions lines in which to work.

But be careful, because this formula perhaps is not valid for some scopes. For example, if our scope is only IT Service Continuity, we cannot conduit a drill: we can cause just the opposite of what we were looking for.