1.) Website Garage (speed, compatibility, spelling, code -incl.alt tags, links). Use this utility to check you final site and repurposing site. (Check home page and secondary pages.)
-You may also want to use this free tool in combination with the Dreamweaver site-wide checking features (site map, link checker and orphan file checker) for all other pages and sites you create for this class.

2.) You should check your server logs to find out which browser is most widely used on your site and design around it. If you don't have a web server log you can use WebTrendsLive http://www.webtrendslive.com/ on your site - it's a free log analyzer.
-More Info on browser readiness: http://www.webmonkey.com