a) Set up a blog on your own website.
If you want to look like a professional at this then having your own website is the way to go. Make sure you choose a reliable web host which has a good uptime track record and good customer service.
You can get a website for free but if you want a reliable site that's not likely to disappear be prepared to pay for it. One of the good website hosts with a reasonable yearly fee is IPowerWeb.
Once you have built up a fair amount of quality content apply to join professional blog networks. Examples of these are: Blogburst, B5media, Orble and Webbleyou.net
b) Set up a blog on a free blog service such as Blogger, Live Journal or Wordpress.
This is how most bloggers start off. These sites are great for personal blogs and for getting the hang of how to do a blog but if you have plans to earn online with your blog it is best to eventually register your own domain and host your own blog on a web host.
Note that some paid-to-blog networks do not accept blogs created on a free blogging service.
Hosting your own blog gives you complete control over how you earn online with your blog. You will have you own identity on the internet and mysite.com will always look more professional than mysite.blogspot.com.
c) Set up a blog on a blog network.
You can still earn online from blogging even if you don't own your own blog. You can either create a blog hosted on sites such as Blogchex, Gather and DigitalJournal with their revenue earned directly from advertisers, or other means, or you can join sites such as 451press, Weblogsinc and Blog Republic as a freelance professional blogger and make regular posts.
You have to be capable of very high standards which make it difficult to get in and what you write may become owned by the blog network and you will not be able to use it anywhere else.
Which ever route you choose you get paid to write or blog about a product, service or anything required by a customer.
Amount paid varies greatly depending on how popular your blog is. The more traffic you get the higher you are more likely to be paid. Study the terms. You may be required to write a minimum of one post a day for a set amount of time or just write a single post from time to time.
What are the requirements for a paid blog?
You will first need to write posts to build up a sizeable amount of content. Paid-to-blog networks do not accept new blogs with little content and no readership base. Your blog may have to be several months old.
It is quite hard work because you need unique content in your blog to keep readers coming back. You need the unique content to get a high ranking in Google and you may not be accepted until you have a certain page rank or have a certain amount of hits.
Posting on Google AdSense blog networks
You can supplement your online income by using blog networks who use Google�s AdSense programme. These sites are not quite so demanding in terms of quality and content and you may be able to use free articles from other sites in your blog.
In order to be paid by Google AdSense from the number of clicks received on ads embedded in your blog you must first sign up for Google�s AdSense programme before joining these blog networks.
Paid reviews
Other sites such as PayPerPost, LoudLaunch, CreamAid and Blogsvertise, may ask you to blog about a product or service and provide links as required on your blog. Sites such as ReviewMe, ReverseLinks, Buzzbyblog, InBlogads and SponsoredReviews let advertisers select the blog they want to buy advertising space on from the list of registered blogs.
Other methods to earn online with blogs.
If you are very knowledgable on certain topics, sites such as JustAnswer will pay you for answering their members questions. Payment could be a lot higher than regular blogging and you will need to be assessed as to your suitability before being accepted.
Companies are also on the lookout for freelance professional bloggers for their blog. Check out sites such as Bloggerjobs.biz, Jobs.problogger.net and Elance.com
There are also people who just don't have the time and want to build up unique content the fastest way possible. They will pay for you to write posts for them at a rate agreed with yourself. Check out Bloggerforum.com, Earnersforum.com, Goldage.net and Forums.digitalpoint.com.