George needs your knitting help.

Last night I finished knitting all the pieces for George and I tidied up all the ends. So I went to sew it up, and there is where I find I am once again stuck.

It says :
"make up - do not press. Using a flat seam, join shoulder seams, leaving 19cm free in centre for neck. Using back-stitch, sew sleeves in position, placeing centre of sleeve to shoulder seam. Join side and sleeve seams. Make a buttonloop on each front shoulder and sew on buttons to correspond."

So I started googling what a "flat seam" was and got 50 million different sites but nothing that really told me. Any clues?

I presume I butt the two shoulder seams together rather than sew with right sides facing, but how I actually join them I just don't know. Since the whole top edge is around 25cms and I leave 19cms gap in the middle, I presume I stitch up 2.5cms from either end and then stop.

back stitch I know, so that part will be okay.

How do you make a buttonloop?