The predictions or hypothesis can generally be found in the introduction section. Keywords like Prediction or Hypothesis are a dead giveaway, but don't count on seeing those.
The method will generally be found in a section labeled Methods, or maybe Methodology. Pretty easy, right?
An independent variable is a variable that stands alone and isn't changed by the other variables you are trying to measure.
A dependent variable is something that depends on other factors.
Variables can generally be found in the Methods or Procedures section.
The results will usually be in the final section of the article, labeled Results. Some articles will have a Discussion section that will summarize the results and how they support or fail to support the hypothesis.