Value in science is currently measured by the index of citations received via your journal articles. More specifically, the Journal Citation Reports (JCR) is the organism that designates the "value" (in academic terms) of the scientific journals scientists publish on. To this purpose, this organism gives a ranking in terms of what is called impact factor (IF)---to be honest they give distinct rankings but for this post we will stick to the IF. In short and greatly simplifying, this metric is measured as the number of citations the articles of a particular journal has divided by the total number of articles published in the journal. In this regard, the more papers a scientist has in high IF journals the better CV the researcher has. So, as a scientist and wannabe researcher your interest is to publish articles in journals that appear in the JCR list.
In the particular case of Computer Science, publishing in journals is, generally, for free. The journal gets the income by the subscriptions and/or by selling the manuscripts to particulars (from $5 to $40 USD per article), and trust me when I say that they receive money. To put this into purely quantitative terms, a very famous publisher currently gets nearly $100000 USD for one year of subscription to their associated journals.
The peer review system, which I am sad to say it is deeply broken, is the way a paper is accepted for publication or discarded. Reviewers, typically, do not receive a single cent; they are volunteers and they have a deadline of 20 to 40 days (it depends on the journal) to emit their judgment. Then, as a young and unexperienced researcher, you submit your paper to your favorite journal and wait, and wait and wait. Forever. As an illustrative example, we submitted an article to a famous journal on December the 19th, 2011 and today (August the 2nd, 2013) we are still waiting for the final response. Short after emailing the editor, we passed the first round and resubmitted the manuscript with the changes the reviewers kindly suggested. That was on March the 3rd, 2013. It is not necessary to tell that we are still waiting. But this is not an isolated case: I have many colleges that waited a couple of years to get their papers published. And that is not a nice thing. In my honest opinion, we, researchers, have to get involved and solve this major scientific bottleneck.