He writes, "I'd thought for ages that my wiki page was very unbalanced so I decided, at last, to do something about it.. What I don't understand is that, if I don't fill in the details, who will?" And he is correct.
We need to be out there looking out for these people, not everyone is aware of the We Got Your Wiki Back! project. Please get the word out, we can't let them directly edit their own page, but we can help them by listening to their concerns, discussing the changes on the talk page and reading over all the links (ect...) that they can give us. Everything has to be vetted, your reputation as a editor is also on the line. You can't just put up whatever someone says, you need to go to the source and read it yourself. When the citation says "accessed on date" that isn't only a check to make sure the link works, but a way of saying "I went here on this day..."
Do let the subject your working on know you are doing so. It is important to them to know that someone cares and is watching their back. Listen to them, they might be able to give you some great articles to read that you can cite.
They probably aren't aware of the rules to editing Wikipedia, they may not understand that you will have to really edit down their suggestions to just a sentence or two. Reassure them that a well written blurb may lead the reader to check out the cite and follow it to the real article.