InsideCRM offers 101 Five-Minute Fixes to Incrementally Improve Your Web Site. The article covers improvements in the areas of copywriting, usability, search engine optimization (SEO), accessibility, design, and disclosure (legal).
What's nice is that almost every "fix" is linked to a more in-depth article with more details on how to accomplish the improvement.
In the next few weeks, I'm going to be diving back into examining winery Web sites (and their specific issues) here on The Winery Web Site Report, and this is a good place to start. I'd also love to hear readers about exceptional winery Web sites (tell me why you think they are exceptional).