I will give you my two cents based on my experience (lots of scientific research in college, masters program, and dental school w/ oral presentations at Harvard, around the country etc.).
A comparison between conservative and liberal economic policies is a very broad topic. Do you have a few specific policies you are interested in?
My recommendations:
1. Choose a few specific policies that you are naturally interested in (if you are free to choose the topics), limit the number to two or three
2. Try to develop a general outline for your paper (note: it is sometimes necessary to do some reading about the topic so you can be well versed prior to developing your outline. Try to come up with a stance or a postion that you want to defend or support prior to creating your outline).
3. Go online and find relatively recent ACADEMIC articles published by reputable authors (university/academic scholars can generally be trusted and can be considered "current"); stay away from media generated publications, personal websites etc., etc. as these can be biased
4. Find articles, skim for supporting/contrasting information that relates to your outline
5. Modify outline/direction of paper as needed
6. Start writing your paper
A few notes:
-be very careful to reference your supporting documents
-don't over use quotations just to fill up space
-start early
-do some soul searching and try to believe in what you are writing (it will make writing your paper much more easy and your paper will be much more compelling to the reader.
-send your paper to someone else for revisions prior to handing it in.
Good luck!
Doc