I believe that some of those RSS links are new since I asked about ways to subscribe to someone's blog. Without seeming like I think the world revolves around me, I thought they were added in response to my inquiry.
With both Yahoo! and Google, there should be an icon in the upper right to change the number of entries shown. Google updates itself every 5 minutes or so, but sometimes it takes a bit (unfortunately, I've seen as long as 12 hours or so) for the RSS to propagate. It depends on the feed.