Yeah, vitamin D is next up on my supplement 'to do' list. Although I do get some from my liquid mulit-vitamin. I recommend naturalnews.com as a source for health related info.
Vitamin D myths, facts and statistics for instance.
I found it interesting/worth noting that people with dark skin pigmentation may need 20 - 30 times as much exposure to sunlight as fair-skinned people to generate the same amount of vitamin D. Being an albino is actually helpful in generating vitamin D, who would have guessed?
For the highest quality vitamins I usually start by looking at the
Integrated Health website. They also have a tendency to include useful cofactors. And the site is very educational too.