A word on the dog training industry
The dog training industry is only self-regulated, meaning there is nothing stopping anyone setting up online and saying they are a dog trainer. However, there are several organisations which trainers can become a member of and accredited by. These organisations can differ between their ethics and their code of practices (some organisations will not condone the use of punishment-based training techniques, for example).
I strongly encourage all people considering taking on a dog trainer to look to see what organisations they are a member of, research those organisations, and get a feel of what they are about and what they stand for. You can see my accreditations and organisations I am a member of at the foot of my website.