Hello
I work somewhere that requires me to sort paper piles. I need to look
at the backs of the paper items and then pile them face up quickly.
The first item I look at needs to go on the bottom of the new pile and
so on. If I flick through them to look at the backs of a number of
paper items at a time then pile all those looked at in one go
obviously they will be in reverse order. How can I look at the backs
of a number of items and then pile them so the top one is on the
bottom quickly. I would also be interested in any books people could
recommend/videos/websites on the subject etc.
Thankyou for any help  (dont think badly of the human race because of my dumbness ;)

Pile them back facing up in reverse order, then turn over the stack when done.

A mirror - or two

- strictly speaking it sounds as if you are merging rather than sorting

There used to be stands for sorting: flat base, stiff separators (A-Z,
1-??) between open diagonal supports (like a half opened book). 
Couldn't find them here, but didn't know what to search for.
Often when sorting/merging, it is fastest to do it in two or three
steps.  Say, you have have a stack of a few hundred unsorted sheets. 
With such a stand (1-100) or 4 (1-25, 26-50,...) you can sort the
sheets by the last two digits, and then sort each two digit bunch into
piles by the hundreds digit, starting with the first (01) group of the
first sort, face down.
Obviously, if you have different types of items (e.g. receipts,
orders, invoices), it is convenient not to let people dump them all in
one in-basket.

Does that make sense?