I would include all of my expenditures.
I keep an "expense form" for each quilt, hoping it will come in handy if I ever get a quilt appraised. Also, I want a really good idea of just how much I have invested in a project. I include everything I can think of, from the book or pattern to any templates, and even the fabric pens and 1/4" tape. I keep receipts with the forms.
I also like the idea of keeping a scrapbook of quilts, and since I have done so few, I could probably accomplish the task if I started soon. Hmmm.
I would keep the expense form in the scrapbook, but inconspicuously.
I think I would include the start date, if known.