Here is the next edition of the EzineArticles.com Article Writing: Content Sources and Article Templates Training Series.
Q & A: Review the last 3 months of questions your audience/clients have sent you via email or over the phone. This is a great resource for several Q&A style articles that can address your target's questions (without disclosing any personal information about your audience/client).
Survey: Conduct an email survey of your audience or clients and identify their top 20 concerns or areas of interest. Most surveys will produce too much data for just one article. A single survey can help you easily produce a set of 20-25 articles whose topics were generated by your target audience!
Conduct a Class: Run a free teleseminar for your clients, prospects or ideal market audience. Use it to give your expertise while polling them for ideas and feedback on what they want to learn more about relating to your expertise. You should be able to extract 100 or more article topic ideas from this strategy alone, not to mention using your teleseminar transcript for article content (with some editing to create small 400-750 word chunks of tips).
Blog/Forum/Discussion Board Comments: Compile your audience's comments on your blog post and identify helpful tips, questions, concerns or areas of interest. Just one blog comment from one of your readers can easily turn into an article addressing a question, concern or area of interest.
Keep Tabs on the Competition: Setup email alerts or subscribe to RSS feeds when new articles in your niche are posted. Use these for inspiration only. If you find yourself asking a question just after reading a competitor's article ... answer it with your own article! You can reverse engineer the topics your competitors have tackled and add your unique perspective.
Interview Your Competition: Your competition can be a great source of inspiration, and in this case, content. Interview another expert in your niche via phone or email, record and transcribe it if necessary, and chunk out the content for a series of 400-750 word articles.
Hint: Remember not to include any numbering or edition system in your article title, even though you may be chunking out several articles from one original content source.