The best back up

I started writing on my online journal almost four years ago. It has helped be hone my writing skills and at the same time allowed me to channel my feelings and take about things that are happening around me. In those four years, I have written so many things and posted so many pictures and I am curious if I have to do something to protect my files such as having best online backup. I do not have interest in purchasing expensive external memories and I also lack the space in my room to safe keep it. Having the best online backup is like having a virtual wallet that you could put in and take out cash. It is much safer if you have your valued stuff placed in a safe place in which you have an access 24/7.
There is quite a number of service providers that offer online backup and the question is how reliable is their service? It is our time then to do our homework and ask around who has got the best to offer. A few trial and errors would be acceptable but hitting the right note at first would be good. I really need to do a great decision making especially if it involves a huge chunk of money. I should get a good deal.