My youngest (just turned 2) is the first child of mine that has been to a nursery - my mum used to be my sole child minder. Now my mum is poorly (depressed) and is no longer able to look after my children (3 of them) I was in the same position as you of trying to find a suitable nursery where I felt I could leave my DD with least worries.
I visited a few during opening hours to see how the children were that were in the nursery.
When it came to finally choosing one, I found they were much the same as regards caring for the children, activities, stimulation, care, etc.
The one criteria for me was the opening hours (I work 9 to 5:30 an hours drive away from where I live) but the nursery my DD now goes to is open from 8 (which means I get in to work about 9:10) and finishes at 5:45 (but I have to leave work at 4:20 to make sure I am home in time to collect her) and the locality to my home.
My youngest DD has severe delay development and the nursery I chose was actually recommended to me by my portage worker (not recommended as such, they can't do that, but more along the lines of that they had another child in their portage scheme that attended the same nursery and they thought it would be very good for my DD to attend as it might "bring her on". She has been going for 4 weeks now (although she missed last week as she only goes 2 days and was on anti-biotics and she had to be on them for 24 hours before the nursery could adminster them on my behalf).
She gets a bit upset when I turn to leave but I know that by staying I am only prolonging the agony and that when I leave she is absolutely fine.
I find she gets very, very tired but she does seem to be thriving.
It is very hard leaving her but I have to work, have not got anyone else to look after her so I haven't got a choice.
I am sure you will find the "right" nursery for you.