What should I do if I uploaded my manuscript in arxiv and plan to pass it on a peer reviewed journal?
Based on your profile, I will assume this is a mathematics paper.  In that case, the answer is almost certainly: This is totally fine.  You don't need to do anything.  Just submit your paper to a journal whenever you are ready.

There are two main ways in which posting a preprint could interfere with publication, but neither of them is usually applicable in mathematics.


Double-blind review. In some fields, it is common for the journal to send the referee a copy of the paper with the author's name removed.  The theory is that this makes the review more impartial.  In this case, if you had a preprint on arXiv, the referee might find it by searching for the paper's title; then she would know your name and the review would no longer be double-blind.  This is the issue discussed by the question you linked.  However, I've never heard of any math journals that do double-blind review.  
Prior publication. A nearly universal rule in academic publishing is that you cannot publish the same paper in two different journals.  This is a mechanism to keep the scientific record orderly (so that there is one unique place to find and cite the article); also, for subscription-based publishers, it helps ensure that people have to subscribe to their journal to read their content, and can't get it elsewhere.  So you might worry that if you had a paper on arXiv, a journal would reject it on the grounds that it was already published.  Fortunately, though, I've never heard of any mathematics journal that considers an arXiv preprint to constitute "prior publication".  arXiv is so widely used in math that publishers generally don't object to the paper being available there.  (But I have heard that in chemistry the opposite is true: posting a paper to arXiv can torpedo your chances of publishing in a journal.)


Of course, to be safe, you should check the policies of the journal where you are submitting.  Questions regarding preprint archival are usually addressed explicitly in these policies.

One thing to note: some publishers do not want you to update your preprint with any changes suggested by their editor or referee.  That way, only the journal can print the "final version", so there is still something that they have that the reader can't get any other way.  Other journals say it is fine to update the preprint, making the arXiv and journal versions identical.  Again, check the journal's policies.