1. Skim the article and identify its structure
2. Distinguish main points
3. Generate questions and be aware of your understanding
4. Draw inferences
5. Take notes as you read
The Difference Between Scientific Writing and Academic Writing
It is helpful to familiarize yourself with the differences in tone that you will find between "academic" papers and "scientific" ones (not to say that scientific research isn't also academic in nature).
Academic writing tends to be more informal, subjective, interpretive, generally pulling from a wide range of inter-related sources. Conversational or discussion oriented with multiple possible directions or arguments.
Scientific writing is usually much smaller in scope - a fixed argument or presentation of results based on clearly defined goals. More concise, no superlative language (state your purpose/results and move on).
Scientific writing must also allow readers to easily follow whatever methods the researcher used into order to generate the data that is being presented so that they can evaluate the validity of any conclusions that are made. This can be tricky if the subject is particularly complex, so the author must be sure to to write with precision, clarity and, above all, objectivity - any claims that are made must be based on facts, not emotion or intuition.