Newton Papers: Newton's Waste Book
cudl.lib.cam.ac.uk
cudl.lib.cam.ac.uk
Hi lab notebook is also great if you're intereted in the chemistry side of things! http://cudl.lib.cam.ac.uk/view/MS-ADD-03975/1
He even includes his own ink recipe here!: http://cudl.lib.cam.ac.uk/view/MS-ADD-03975/29
The waste book has been transcribed: http://www.newtonproject.sussex.ac.uk/catalogue/record/NATP0...
But this is quite a complex manuscript, so in this specific case we are still working on tie-ing the transcription and images together!
Can't help being reminded of the old NYT Sunday newspaper joke - for the man smart enough to read it, and athletic enough to carry it ...