Réponse:
First it depends on the nature of the document. Here are my little tips to learn a document.
1. Read the whole thing twice or thrice.
2. write them all down on a paper.
3. try memorizing or putting the content in your own point of view for better understanding.
4. also repeat step 2 in computer. print and paste on your room door or some where that you will see regularly.
I hope this helps