The technique has to be to make the board answer these questions collectively. If you're making a major transformation, you might want to appoint to the board whoever is in charge of implementation. This will not necessarily be the manager of information systems, it could be the HR person or the specialist in business change. The role of the board is to set the business principles and then trust the competent person to implement them. There are dangers in directors becoming involved in the nitty-gritty of technology.
Many companies prefer to outsource their IT, but there can be dangers here, too.
You need to know that your supplier is up to the mark. You need to do incredibly careful referencing and make sure you're not their least important customer. Directors also need to consider IT when making acquisitions. Systems integration is one of the things people leave till last. You think about the people and the financial issues.