Travel to Machu Picchu

- train from Cuzco or Ollantaytambo, either on a day trip, or overnighting in Aguas Calientes. Over nighting allows you to visit the park early or late in the day and avoid the worst of the crowds, and on sunny days, gives you a nice window of reprieve from the beating sun. Don't forget sunblock. Train tickets are probably the most expensive in the world (by km). A one way ticket from Ollantaytambo will set you back 55-80 USD and from Cuzco even more. There is a luxurious service that can cost as much as 700 USD. The rail company, Peru Rail, is run by concession by foreign investors, so much of the money does not stay in Peru. (Some people take this into account when they choose their way to get to Machu Picchu.)

- minibus to Hidroelectrica through Santa Maria and Santa Teresa (altogether around 40 soles one way, allow 6-7 hours, you might have to change in Santa Maria and/or Santa Teresa). Then you can walk along the railway from Hidroelectrica to Aguas Calientes (free, 2.5-3 hrs) or take the train (15-18 USD one way). If you go for this option, ask around agencies in Cuzco as it might be cheaper to buy a package that includes the trains to and from Hidroelectrica, buses from Aguas Calientes to MP, minibuses between Hidroelectrica and Cuzco, accommodation in Aguas Calientes and the ticket to MP. The package might be cheaper than going independently, although you will be less flexible once you buy the package.

The wet season in Peru is from November (often only really taking off in December) until the end of March, so then it is best to include a few extra days for flexibly dealing with delays.