Need efficient wordpress.com and blogger.com sites

Ive read about link building for a while and known create multiple blogs on wordpress.com and blogger.com is an efficient way to build links.
But im a new webmaster know little about those sites.
Who can share me some efficient wordpress.com and blogger.com sites.
Thanks all for helping.
By the way ,dont mind my poor english.

 

Thanks for your info, i'd like to deal with it free.
Is anyone having the list?

 

I think blog commenting using wordpress sites would be very beneficial if the comment is moderated and the blogs are relevant.

 

Good Idea .