Digital communications are changing fast, and keeping up with developments can be a challenge for small businesses. There is no 'one size fits all' solution. Different businesses may benefit from different technologies so you will need to assess your own needs and the solutions most appropriate to meet them.
To help you do this, a variety of organisations offer support and advice, many of which provide services and impartial advice free of charge. Some of these are listed below, but there are others online and offline too.
Don't forget that the Ofcom website has a number of resources for businesses (and contains information in its pages for residential customers that may be relevant for small businesses).