And the two biggest (and best) sites for questions and answers are Quora an Yahoo Answers.
With a fast and easy Google search hack, we can quickly find the questions people are asking on these two Q&A sites.
If you're not familiar...the "site" search operator will limit to Google search results to a particular domain.
The "intitle" operator means that the title of the web page must contain that search term. In this case, I'm using the question mark (?) to find questions people are asking. Although most page titles on the two sites are likely in the form of a question anyway, using the question mark probably helps just a little bit to get slightly more relevant results. You can probably leave it out in many cases
And of course, the last part of the search is dog training. Just replace dog training with your own keywords.
site:quora.com intitle:? dog training
site:answers.yahoo.com intitle:? dog training
Just paste either/both of the search queries into Google, change dog training to your own keywords and check out the questions you can use for your next niche site, report, email, etc.
And both Yahoo Answers and Quora are great places to begin your research for your content...