Here's a quick run down on how to properly research and cite facts for articles.
1) Use proper resources
2) Interview the direct source whenever possible
(See 'accepted query, now what' post for more detailed information on resources and interviews.)
Next, be sure to:
1) Prepare questions ahead of time. This keeps you organized and makes note taking faster.
2) My best suggestion is to always record the conversation. You can find recording devices at most electronic stores (or find apps online). Because laws vary by state, recording a conversation without permission may be illegal. Always ask your interviewee for permission and get that permission on tape. If the interviewee says "no". Turn off the device immediately. If you are able to record the conversation, the audio will protect you any many ways: you can check for mistakes, clarification and you'll make the magazine fact-checkers job much easier (especially, if you take a few minutes to provide a written transcript).
3) Double check proper spelling of any names, proper nouns, etc.
4) Ask for references to other useful, reliable sources.
5) Try to take notes during the interview. I prefer NOT to rely on the recording alone; you don't want to be surprised by a malfunction. Plus, written notes bring you one step closer to a written article, particularly if you want to cut and paste exact quotes or statistics. (Note: use the recording to confirm the quote/stats are correct.)
6) Provide your notes, transcript (and/or the actual recording if requested) for the fact checkers. For national publications, I provide two copies of my article. The first copy is the consumer version. The second connects the facts/statistics to the source. Remember the good old bibliography? If you're concerned about the traditional bibliography format, visit an online site for proper citations. Most magazines, however, are happy with citations that are easy to confirm/follow. Here are some quick examples:
1 Dr. Douglas, Eric interview, transcript page 4, audio 1:10,
2 Need for Later Start Times, http://aapnews.aappublications.org/content/35/9/1.2.full
8) Please note, these are my suggestions based on the editors I've worked with. The best option for you really comes down to the specific expectations from your editor.