Best things to look for in a daycare?

I'm ready to put my 1 year old in daycare and go to work instead of work from home. I want him to gain good social skills and learn and I'm told this would be the best way. What is the best things to for? Is there any specific things he should or could be learning? What are some good questions to ask? And how can I help my son easier adjust to not being home or with me and hos dad? I'm sure you can tell but this is my first kid and I want to be sure I do what is best for him.