Ankush,

A web 2.0 website is a website where user generated content can be produced such as through comments or perhaps a forum. The term web 2.0 is fairly antiquated and there are dozens and dozens of websites that could fit this description. For example blogger.com or wordpress.com are web 2.0 properties.

In order to get links from sites like these, web marketers will create free accounts on them, post articles and place links in those articles back to their websites. This is a process known as tiered link building where the web 2.0 is the first tier.

More on that here,

what is a web 2.0 property/ page ?

Best,

Shawn

Make free blogs on tumblr, blogger, weebly, wordpress etc etc.

Those blogs will be your web 2.0 properties.

You have to build Web 2.0 sites. I use them in a tiered structure to get the very best link juice.

another one might be squidoo. also include bookmarking and blog comments into your strategy
it´s just all a whole lot of work

Other thing is finding a list of web 2.0 sites where you can create content and you can use them for link building purposes, only blogspot, and wordpress wouldn't help, you need to use several web 2.0 sites.

Read this guide for more explanation.

What Are Web 2.0 Websites And How They Help in Boosting SERP