Matt Levenhagen over at the Grip Success blog has a good series going on niche research, with more to come.
<a href="http://www.gripsuccess.com/niche-marketing-articles/28-niche-research/123-niche-finder-series-keywords-and-competitive-research.html" class="latestnews">
"Niche Finder" Series: Keywords and Competitive Research (Part 1)</a>
<a href="http://www.gripsuccess.com/niche-marketing-articles/28-niche-research/124-qniche-finderq-series-researching-for-worthy-niches-part-2.html" class="latestnews">
"Niche Finder" Series: Researching for Worthy Niches (Part 2)</a>
<a href="http://www.gripsuccess.com/niche-marketing-articles/28-niche-research/125-qniche-finderq-series-open-your-favorite-keyword-tool-part-3-.html" class="latestnews">
"Niche Finder" Series: Open Your Favorite Keyword Tool (Part 3) </a>
<a href="http://www.gripsuccess.com/niche-marketing-articles/28-niche-research/126-niche-finder-series-most-relevant-and-targeted-keywords-part-4.html" class="latestnews">
"Niche Finder" Series: Most Relevant and Targeted Keywords (Part 4)</a>
<a href="http://www.gripsuccess.com/niche-marketing-articles/28-niche-research/123-niche-finder-series-keywords-and-competitive-research.html" class="latestnews">
"Niche Finder" Series: Keywords and Competitive Research (Part 1)</a>
<a href="http://www.gripsuccess.com/niche-marketing-articles/28-niche-research/124-qniche-finderq-series-researching-for-worthy-niches-part-2.html" class="latestnews">
"Niche Finder" Series: Researching for Worthy Niches (Part 2)</a>
<a href="http://www.gripsuccess.com/niche-marketing-articles/28-niche-research/125-qniche-finderq-series-open-your-favorite-keyword-tool-part-3-.html" class="latestnews">
"Niche Finder" Series: Open Your Favorite Keyword Tool (Part 3) </a>
<a href="http://www.gripsuccess.com/niche-marketing-articles/28-niche-research/126-niche-finder-series-most-relevant-and-targeted-keywords-part-4.html" class="latestnews">
"Niche Finder" Series: Most Relevant and Targeted Keywords (Part 4)</a>