Yahoo! offers a suite of tools to help their advertisers set up their accounts.
SEO Book Keyword Research Tool: cross references the Yahoo! Search Term Suggestion Tool, the Yahoo! View Bid tool, and all the Google keyword research tools. General Keyword
Yahoo! Search Term Suggestion Tool: shows the frequency of searches across the YSM network for the prior month. Inventory Overture.com
Yahoo! View Bid Tool: show the highest bidders for a specific search term. Bid Tool
Yahoo! Advertiser Workbook: free downloadable ebook released by Yahoo! to help you get the most out of your YSM campaign.