When i moved areas i posted on our local horse page and got some answers, it was only when i was actually here and met people i found out about others though that were less well known so word of mouth is the best, especially if you can ask local instructors or farriers etc as they go all over the place and will know the less well known places.
All yards I've been on have either been through tack shop ads, facebook, friends or word of mouth. Current one which I never want to leave from is off an old Facebook advert I found whilst searching.
My current yard I found by word of mouth. I knew the YM, but didn't know she had set up a new yard near my house until I bumped into an acquaintance who mentioned it. I was on a good yard 8 miles away, but moved and my boy is now just 600 yards from home. Been there nearly 3 years now and love it.