I have sanded and stained my dining room table (minwax) what do I need

Hi Linda, Polyurethane is probably your best bet. It's very durable!

Good luck!

I would put a coat of satin finish varathane on it with kids.

What about getting a thick piece of glass cut to fit it? Or would the kids break the glass?

At least three coats of a water based polyurethane. Use a foam brush for a smooth finish.

Polyurethane and 3 or 4 coats, especially if kids will be playing and crafting on it. Probably be a good idea to buy some of those vinyl placemats for$1 at the dollar tree. Tape a bunch of them together on the back with duck-tape, flip them over and you have a giant table mat.