I was there for 3 months just over 10 years ago, I booked my daytrips when I got there through a company called inca wasi. They had reps waiting in the arrivals hall in the airport. I done the inca trail and stayed overnight In agua caliente then caught the train back. I also went to the floating islands on lake Titicaca. After that I headed to Arequipa and done the colco canyon, nazca lines and islas ballestas. Cuzco is great for a night out, I drank in mama Africa lot where the chicas loved the gringo! They have a facebook page which is worth checking out. I'd also recommend staying in Hotel Frankenstein, it's owned by a german bloke who doesn't mind if you bring guests back!