Fair enough. But even after he's done all the stuff recommended on this thread, he still won't really know whether his writing is any good or not... you need a wider audience than a few well-meaning beta readers to figure that out. (How many posts have we all seen from writers who say their betas loved their stories, and then we read the section posted for critique and there are serious, serious issues with it?)
Well, there's definitely an art/skill in choosing beta readers, and evaluating their feedback. But I put huge, huge store in good beta readers, and I don't consider the "OMG you can put words on a page, you rock!" people to be beta readers. They're cheerleaders. ...or just idiots.
I know where to go when I feel like my writing is bad, and want to miss prose for a while. And story structure, plot, SPAG, oh hell everything. The catch being you are not allowed to point any of this out, as it outlined in the rules. It is a bit of pain in ass. Though the trade off for holding back, is knowing that you write a zillion times better than those folks.