We took a less traveled route using the Lemosho Glades Trail.
We had never been to altitude other than two business trips to Mexico City years before. Because of our inexperience I decided to take 9 days to get to Crater Camp then summit on the 10th morning. Even with extra days we didn't sleep at Crater Camp but beyond a headache on
occation and not being hungry up high, we did just fine.
A rule of thumb is 6 days up 60% chance to make it. 7 days 70%, etc.
One third of the attempts, about 10,000 people per year, don't get to the top. Each person is different, of course, but an extra day or two on the trail will help your confidence if you are worried about getting sick.
50% of mountain climbing is mental. The total distance you will hike is 50 miles. Know before you go to Africa that you can hike that distance (do it with 3 or 4 hours hikes with some back to back) as you break in your boots (We took two months to prepare and did all the hikes in Wisconsin...no altitude here). If you are spooked by the altitude, add some days to your trip. (I took the 9 day option because I had no altitude experience, I was 53 and had no intention of going all the way to Africa and fail). Also, it's beautiful and there was no reason to be in a hurry, it was a father/son trip.
This is the article I wrote about our trip. It gets into more detail about our preparation and choices of route, etc.
http://www.mtkilimanjaro.org/06-01/nothing-but-sky.htmlIt is an awesome experience...have fun!