I am hearing about HTML5 & CSS3 for a quite long time but not able to try it out.Today I got a chance to play around with HTML5.As always I started with platform to run ie what are the browsers supporting HTML 5.I got a good list .
Table of browsers supporting HTML5 & CSS3 and their versions.
In this above table I recommend Chrome.Then I started for editors.But I was not able to find a good one as it is a new technology.But there is one online editor which I feel ok for starters.
http://rendera.heroku.com/ – Online HTML 5 editor
My next search was to find out what is new in these.I got another list from my favorite site W3Schools.