I do not recommend that anyone try to make extra money by doing data entry. There are a few reasons for this and I will go into them in more detail. For the most part, it is like a scam because you can never really do enough work in order to make anything like a decent wage.
Doing data entry from home is not going to produce as much income as, say, writing freelance articles would. Instead of entering data, consider writing articles instead and getting paid a few dollars per article. This may not sound very exciting, until you consider the implications of writing about 5 to 10 articles every day. When you do that with discipline then the numbers start to work in your favor and you can make a real part time income from it. At worst, if you are writing 10 articles per day you will easily clear 500 bucks for the month, and some people can do this in right around 2 hours of work per day. It all depends on how fast you are at composing new material.
Now another alternative to online data entry work is for you to publish new content on your own websites, and then promote your site to the point that you start getting natural traffic to it every day. This sounds like a complicated process but it is actually fairly easy to accomplish if you are willing to work at it over time. Eventually, you will get traffic flowing to it every day and then you can do various things to make money from that daily traffic. At this point the income you make from your website will be largely passive and you will not have to work much, if at all, in order to maintain it. A nice setup if you can put forth the effort to make it all work.