When I saw the title of this post I thought "Who is writing about MY boy!?" Then saw it was you and had a giggle - I think our boys are a lot alike!
My DS learned this about 2 weeks ago, and learned it FAST. One day he put his hands in mine and grunted with all of his strength to get himself to standing, and about three goes of that and he was instantly up, no struggle or anything. 24 hours later it was the sofa, and then that's that - he can't see something and NOT pull himself up on it!
The first few days, maybe a week, he was very unsteady and unstable when he got to standing up, and a bit scared even. I did stand with him, held him up, hovered behind him, etc ALL DAY. Driving me mad.
I'd say within a week or so he is now comfortable and stable standing on his own, so I don't hover any more. I also tried to teach him to fall, or to at least not be as upset when he does fall, so that has helped. I do worry that when he is using the coffee table that he will fall and knock his chin on the table and bite his tongue, so I watch if he is there, but the sofa I just leave him. He uses the washing machine as well, and is strong enough to pull the door open from locked, but as it takes a good pull, he ends up hitting himself in the face with the washing machine door. So that's an ongoing battle for us.
This weekend I dragged the travel cot downstairs to use as a playpen so that he can go in there when I can't keep my eye on him the whole time I'm in the kitchen and can't deal with the washing machine issue. Just spending a few days making the travel cot into a super fun game for him so that he doesn't think of it as punishment -- of BabyJail as DH calls it!
I'm hoping that it only goes on another couple of weeks before he is really stable and I can ease up. That, or I'm going to duct tape some pillows around his head....
PS Can you pop over to my 10month old naps question on the EASY forum?!