In the regional boards I follow there seems to be a much higher barrier to entry for Chowhound newcomers than the topical boards. On some of the boards DaveMP is promoting the "dish of a month" which is a bit slow to catch on with regular posters, but I think is a good idea because it is a way newcomers can contribute easily to something that is current (cookbooks of the month and other threads are possibly why Home Cooking as one topical board is more friendly). The Digest publishing those entries with photos is also useful and I think its important that the staff focus on encouraging newcomers. However, encouraging sincere newcomers is a good practice for contributors too, but you will never gain consensus to incubate and nurture new posters (and there is more than a few bad apples which sometimes spoil it for others).
Although the idea of introductions is not rare and I hate that many forums require it before posting, I wonder if it wouldn't be useful for well-meaning newcomers, if there was a way to keep the content fairly fresh and the threads manageable. There are also contributors who enjoy welcoming newcomers, so its a place where they can also provide a word of support and no risk of that being drowned out in a conflagration of a review post. The post could either be linked from the "Welcome to X board" or a sticky, although I sort of like the former as it would rise and fall like normal posts. And having a monthly thread would keep it fresh by rolling over regularly, but for instance if someone says "hello" in June and then contributes a post in December, the "hello" post is still available in their posting history so perhaps they won't so readily be questioned "welcome to chowhound, but this is your first chowhound post..." And for those who don't introduce themselves instead of saying in a thread "please post your 2 favorite restaurant experiences in <city>" which will later get buried, the first-time poster could be pointed to the introduction thread to do those honors. We will still get hacks who sign-up just to skewer a beloved restaurant or promote another and there will be posters (like myself) who don't like introductions, but it levels the playing field for those in-between and also gives them a safe place to make an initial post where they won't get seared by the radiant heat emitted by more experienced contributors.