Preparation

Yup, @Afraser is quite right - aplace to keep all your reports/results etc is a must. A blank journal - I wrote a few lines in mine every night, as much to make sense of things and keep track of what was happening to me as anything. The best gift I got was from my kids - they bought me a sodastream because ordinary water tasted so awful when I was having chemo, but sparkling was lovely, especially with a squeeze of lemon!
Doing a mad clean and tidy before everything kicks off will at least keep your mind off what ifs and make you feel as though you're achieving something