When you use the wordpress.com site it's free but if you want to publish a blog with your own domain using the wordpress platform you will need to pay for a hosting service as well as pay for the domain.
The wordpress templates themselves are free.
That depends. There are free services, where your hosting costs are gratis because a company hosts them, like Wordpress.com, Blogger, LiveJournal, If you are willing to pay for domain and hosting, then you can install a free blogging platform - like Wordpress.org. Technically, the blogging platform is free but you pay for your own hosting and domain name.
Not necessaraly. You can use sites like wordpress.com or blogger.com and that won't cost you anything.
Another option is to host your blog independently and then you'll need to purchase a domain name and hosting service.
The only cost involved in starting a blog is the time you put into it. There are numerous free options to create a blog (See links below).
some do some dont
Both can cover any topic
Google blogs are free to use. If you wish to advertise on a blog you will have to pay for listings and click through amounts. If you want to use your Google blog to make money you can allow them to host relevant ads on the page.
Some of the most popular money making blogs are: Huffington Post, Mashable, Engadget, Perez Hilton and Gizmodo. The number one money making blog is the Huffington Post.
It is possible to make money writing by publishing books or papers. Internet users can also write original content for their own websites and blogs, or write for websites and blogs owned by others.
The easiest way to earn from blogs is from placing ads.
Have more blogs and Google put more ads , and you get more money.
No, it does not cost money.
No it does not cost money
No it does not cost money.
No it does not cost money
Yes it do cost money
It depends on which version you get there is a way for it to cost money. But it is most likely to tell you whether it will cost money or not! :)