Many bloggers have started blogging using free platforms. I personally would not suggestion this option, as you barely own your own content and images on some of those websites and I have personally see that they can lock your account for one or another reason, free blogging spaces are not very professional option and your blog will be highly limited. If you can’t afford paid web hosting service and your own domain name, you still have several options.
This is free micro-blogging platform that offers reliable service for creating your own blog with your own design. I personally see Tumblr as a hybrid between Twitter and WordPress. You may need to have good knowledge of HTML and CSS to make blog really attractive. There are several apps for mobile phones too, so you can post updates by your phone. If you own domain name, the only option is just to forward it, which is not very SE friendly.
You can submit text, images, videos, etc.
Bought by Google few years ago, Blogger is flexible platform where you can also host your own domain name. It is probably the easiest option to start blogging. Interface is very easy to start with and there are many written guides. As well there are number of applications that you can install on your BlogSpot blog and make it more SE friendly or just add do-follow links on comments.
Based on WordPress, probably the most popular blogging CMS, this free service has cut all the extras of WordPress flexibility and plug-in support. Again you can host your own domain name.
There are many other options that work mentioning - SquareSpace.com, LiveJournal, TypePad, etc. Even you can start blogging at WebmaisterPro, we also offer free blogging platform for our member.
Now let’s face the reality – to build a successful presence online through blogging, you need to invest some money – web hosting, domain name, good design (probably premium template) and some premium plug-ins. This investment is considerably low – probably no more than 100 bucks a year, the rest is your time and skills.