Any serious paper (ie a journal not a trade magazine) will have a few common points. Here are things I definately include when I'm writing one:
[*]Well written abstract. Search engines usually only search the abstract. Is the abstract concise, clear, and relavant? Is it written in a way to get hits on searches that want the paper and not any other searches?
[*]Clear introduction. What is the paper about? Can you answer that without reading the whole paper? Do you understand the background (assuming you already have a basic knowledge in that field)? Are the goals of the paper clearly stated? Is the rest of the paper going to achieve those goals (you should know without reading the rest if the introduction is good)? Are the new ideas and relavant terminology properly defined?
[*]Clear description of research. Can you follow step by step what was done? Was the logic complete and accurate. Ie: a=b, b=c, thus a=c is logical and complete. But a=b, d=e, thus a=e is not complete and may or may not be logical.
[*]Concise and useful conclusion. Does the conclusion help summarize the paper? Are the conclusions clear from the paper or were they pulled out of the authors a$$? I once had to review a paper in a class and the formulas in the conclusion had nothing to do whatsoever with the graphs all throughout the paper. In my review, I derived the proper formulas from the paper's data and got the top grade in the class.
[*]Overall. Is it written with proper spelling, grammer, with proper citing? Is the work truely new (the authors cannot print a paper twice or copy other peoples work)? Is the paper laid out in a clear and meaningful order?
That ought to get you started.