I recommend your set be at least 14x14, but 11x11 was the size used
by the old Parker Brothers sets. A factory second Battlemat with
1" hexes is about $15 including shipping. An f.s. Megamat is about
$24 including shipping. If you have access to a sewing machine, I
recommend you sew white and black thread along the four edges to
indicate whose sides are whose. This might also help keep the edges
from fraying. It is probably best to store the board rolled up face
out. The Chessex site has further advice on taking care of the mat.
I DON'T recommend that you buy the Chessex stones.

Standard Go stones would work fine with these mats; you can get them
at https://www.yutopian.com/yutop/cat?category=sb
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If you don't know what cookies are, then you probably do have them
enabled. The least expensive stones are less than $11 including
shipping, but you would need to file the plastic burrs off the edges
of almost every stone. "Official" stones (or glass stones) look and
feel much nicer.

So, you could get a decent 15x15 set for about $26 including shipping,
or for $41 total you get the nicer "official" stones. Grocery stores
are full of plastic tubes (usually containing some sort of food
substance) which you could use to store the rolled up board in.

You can download and print out the rules here:
http://www.abstractgamesmagazine.com/hex.html
The rules are very brief, and could easily fit on a single page.

If you have any question, I would be glad to try to answer you.

David