My family have travelled to the US several times from the UK. My husband was banned from driving for 12 months (drink driving charge) in the UK, but it was over 2 years ago. Will this have a negative impact on our travelling? Also, what documentation would he need if he is allowed to go? Would he have to visit the US Embassy in person to apply?
A drunk driving conviction by itself does not make your husband inadmissible. No need to go to US Embassy or special documentation.
The ESTA form asks applicants the following:
Have you ever been arrested or convicted for a crime that resulted in serious damage to property, or serious harm to another person or government authority?
If the answer is no, he's fine to use ESTA, otherwise he needs to apply for a visa.