1) Blogger:-Most of the bloggers prefers bloggers for getting starts with blogging. The blogger is owned by google so google products can be easily accessed in blogger. The syntax of the blogger domain is like domainname.blogspot.com.
2) Blog-:Another famous free domain providing with sub domain provider. The web building tools in blog is very useful to the beginners. And through the blog one can make a seo friendly blog and after making some earning one can buy domain and connect with the blog. The syntax of the domain is like domainname.blog.com
3) Webnode-:Actually this is a domain registering center in which it provide domain names at cheap price. Beginners can use their free domain offer that is domain name with sub domain. After making money with the site one can buy domain name from the webnode itself. The web builder in webnode is amazing and it is very easy to use. The syntax of the domain name is like domainname.webnode.com
4) Webs-:This is also a domain name registering center as like the webnode in which the domain names are sold at cheap price. As part of their service they also allow the members to start with free domain with their sub domain. The syntax of the domain name is like domainname.webs.com
5) Wordpress-:Another great free domain with sub domain providing site just like blogger and blog. They are very famous for their web builder most of the .edu domain names are using wordpress web builder to make blogging comfortable. The syntax of domain name is like domainname.wordpress.com
6) Dot.tk-:This is actually a free domain name provider without giving any type of sub domain with the domain name. But the domain extension is contain their sites extension that is you would not get .com, .net or .org domain name extension only get .tk extension. The syntax of the domain name is like domainname.tk .
This are some of the best sites to getting start with blogging one thing one should have to be careful there are many disadvantages as well as advantages are there for free domain so be aware about that. All the best.