There's more info on this website - directions and a map.
http://www.breedingcentresharjah.com/Wildlife%20Centre.html
It's a great place - we all loved it there.
Get onto Emirates Road towards Sharjah, go over national paints bridge, follw the road until you see the signs for the airport, take the exit marked Sharjah Airport and Al Daid, follow this road and it is signposted from there.