if u know about blogs creation it just like blogs creation but in this u get some more useful things like comments rss feeds n other for the better knowing web 2.0 visit this http://www.promote-site.com/web-20-page-creation.html
think of web 2.0 as amazon.com and how that website works . example: hover overs, recommended products based on your surfing, rattings/feedback, blah
On Web 2.0 you can make manythings as well as bussiness like comments in some products and many others!