I just returned from a month long trip through Nicaragua, and Panama, and was lucky enough to discover a guide here on TripAdvisor named Rodolfo Ortega. I emailed him on short notice about getting a tour through Granada for the first day of my trip. I have to say..I'm glad that I did! He was great! extremely informative, great to be around, and he spoke perfect English (which was good for me, I'm still learning Espanol)
Anyway, I had to buy a bus ticket for my onward travels, and he was even kind enough to go to the bus station with me during our tour. Out of my month of traveling, that first day with Rodolfo was the highlight tour of my trip. Anyone heading to Nicaragua? email Rodolfo. You won't be sorry.