Every writer has experienced writer's block at one point or another. My suggestion would be whatever article or assignment you are trying to get through, the part you are stuck on start brainstorming. This can also help if you are having trouble with getting started as well. Write down ideas that come to mind, make a list; for example if you are writing about "The History of Jamestown" your list could look something like this:
a) What type of fashion do the people in Jamestown wear?
b) Were did Jamestown get its name?
c) Are there get famous people who were born or once lived in Jamestown.
Then you can take your list do your research, and hopefully this will give you a jumpstart to getting pass your writer's block.