What a good question!
I don't have a map, but can suggest one or two places to visit on the way to or from Key West.
The Wild Bird Rehabilitation Center is located at MM94 Bayside in Tavernier but the sign into this place is tiny and if you blink you would miss it. Don't miss it though as it's a great place to stop and see the wild birds (and cute racoons) which have been rescued and are either residing there permanently due to some quite serious injuries or are being rehabilitated for eventual release back into the wild. The owners are doing a fantastic job in looking after an ever-growing population of birds, some of them quite rare. I have found a review here:
When we visited, Laura Quinn (presumably now 75 years old) was on the boardwalk with her leg all strapped up carrying a falcon. Apparently she had broken her leg falling from a tree after climbing it to rescue an injured bird! That's dedication!
The center is absolutely free to visit but has a donation box for visitors to leave what they wish - we thought it was well worth the suggested $5.
Another place to visit is Robbie’s Marina on Lower Matecumbe Key at about MM77.5 bayside where you can buy bait to feed the wild Tarpon. More info here:
A good place to see the Key Deer is at No Name Key. You will need to turn off the main road at Big Pine Key - here's a map:
You could also pay a visit to the Bat House: