Personal recommendation is always best. Start with any friends or family who have tennis lessons and ask them about how good the coach is, and the club or organisation generally. If you don't know anyone who has tennis lessons, you can do some research. A good place to start is the Lawn Tennis Association website. There you can find the name of LTA registered coaches living in your area, and if you click the 'what to look for in a coach' button you will also find helpful advice on choosing the right person for you. This is especially important if you haven't played a lot of tennis, as this advice will help you know if you are being well taught.

If the LTA can't find anyone local, the next step is to try your nearest leisure centre. You could arrange to play a game or two there - they may be able to help you find a partner if you don't have one - and then if you ask around a bit, probably someone who plays regularly at the centre will have some advice about coaches. Hope this helps.