Well, there can be a lot of variations in thinking of me and others. So far whatever i have learned in this tech world gave me a clear idea what you should know if you want to be a blogger or a programmer or just a person who have a decent understanding of computers.
The minimum reuirement is ANY computer language. I would suggest C as it is one of the easiest language to learn. You may also learn c++/java if you wish. If you want to learn gui based applications then VB will definitely help you.
The next thing you should know is any server side scripting language. I would suggest PHP as it is just like C codes inserted between HTML tags. So if you know HTML and C then its just a cakewalk for you.
One more thing which you will require very frequently is some query language to understand the flow of data from the database. The easiest of all is MySql.
You may also learn some more languages as per your understanding and requirements but the ones i have mentioned here will definitely help you. If you want to add something then feel free to comment here. Thanks for reading techian. Stay tuned. Much more to come.