Thanks Riss!
I was just doing some research on a similar site.
Found at the May is the best time to go:
May is the best time to visit Machu Picchu – just after the rainy season (so everything is lush and green) but before the tourist rush. June – September is quite busy. December – March is the rainy season and is relatively quiet. During these months you run the risk of mudslides which can block the railroads and leave you stranded for a few days.
Also, there are two ways to get to there. Either by trail or by train. There are several trails to take, but I think I'd probably go with the Capac Nan, which is the original Inca trail. It's a 4 day hike covering 28 miles of terrain. The journey starts at 8400 feet and ends at 7800 feet with a trek through two mountain passes, one of which is at 13,000 feet. The altitude sickness is my biggest worry. I've been to Leadville, Co and felt very mild effects of this and scared that heck out of me. I had to clear my head and remind myself I wasn't having a heart attack...and the feeling soon passed. It recommended though, that one stays in the Sacred Valley a few days in order to get acclimated.