Dave C wrote:
We just purchased a new/used house. The kithchen counter is a ~ 5 x
10 foot (2 inch high) oak butcher block surface. With time, it now
has several "stained" spots (sorta black areas) and many scratches.

I would like to resurface that counter, and I am looking for
recommendations. Ala would one prep the surface with a cabinet (aka
card) scraper, or maybe a tool akin to a Stanley #80 scraper? Other
options.

Once the surface has been prepped, what would be a recommended surface
cover - ala a specific oil, where food prep will occur.

I am retired, so time is not a key issue. I do want the finished
surface to look nice and last.

I would be most appreciative for any/all advice -dave

The black staining could be from iron/steel combined with moisture and
this is best bleached out with oxalic acid - available on ebay and
possibly chemists. Search on wood working sites for application and
dilution.
This does not happen with stainless steel so eliminate plain steel and
cast iron from coming into contact with the oak.