My son started to go to Nursery since he was 6 months old.He is 3 now. There are lots of good nurseries it dependends where you are staying.If you let me know where you stay i should be able to tell you nurseries in my area.
From my personal experience though i would suggest you should look for a childminder and if you find really good one nothing like it. Because my son used to fall sick every other week with infections.His doctor said it's good for his immune but i went through horrible colds and sleepless nights because of that. I am not saying if he goes to childminder he wouldn't catch it but at chilminder it will be less and he will get more one to one.And then when he is 1 1/2 he will need more interaction and then you can look into nurseries.