The following stages may be useful:
Find texts that are suitable for your assignment.
Read and understand the texts.
Find the relevant ideas in the texts. Mark them in some way - write them down, underline them or highlight them.
Make sure you identify the meaning relationships between the words/ideas.
Read what you have marked very carefully.
Organise the information you have. You could give all similar ideas in different texts the same number or letter or colour.
Transfer all the information on to one piece of paper. Write down all similar information together.
Paraphrase and summarise as necessary.
Check your notes with your original texts for accuracy and relevance.
Combine your notes into one continuous text.