What questions would you ask a social media consultant who you or your business wants to hire to grow your brand's online pressense/community?

The big two would be a list of the various social media outlets they have worked with and have experience with as well as a list of companies they have worked with/for.

What type of social media do you prefer...

Asking for a portfolio of work done would be a good idea also, especially blogs created and presences created on YouTube, FB, etc.

Another good question would be to give the candidate a scenario of an issue that could result in negative feelings among the social networks and ask the candidate what the first steps would be if they were in charge of the response. As many people involved in social media have to be able to react rapidly to minimize damage among the social networks they utilize it would be a good test of how quick the candidate is on their feet.