i have to do an essay in class linking 3 texts AWAY, SEVEN YEARS IN TIBET and A TRACK WINDING BACK i have no idea how to do this
If your teacher will allow you to bring the books and some notes to class for this essay, be sure you do so ... and use them.
Notes -- I teach students to make lists when preparing for a comparison (similarities, links) and/or contrast (differences) paper. For this you'll need a separate sheet of paper for each book. On each sheet of paper, make a list of the elements of the settings (time and place), the main characters and their traits, the main actions in the story and their significance, and finally any "angle" that seems to be in common with the other books.
By "angle," I mean this: Perhaps the main character in each book is on a journey and on his/her way to the destination, comes to a major realization or conclusion about life in some way. Or perhaps the settings in each book are similar -- e.g., all taking place in difficult terrain and severe climates. (Hint: Authors usually do this to show how each msin character gains inner strength as he/she progresses through the story.)
Take your notes and books to class, and once there, you should be able to jot down a plan or outline for your paper. You should also (after all that list-making) have some kind of idea for a thesis statement in your mind; write it down, too. Once your thesis statement and plan/outline are completed, dive into writing the paper, starting with the body of the paper. Save writing the intro and conclusion for last. You probably won't have time for a rough draft and a final copy, so the plan/outline needs to be GOOD. When writing a timed essay (which is what an in-class essay is), you should spend 15-20% of your time planning and the rest of the time writing that draft and correcting it.
What you will probably turn in is a corrected rough draft, so don't hesitate to re-read it once you've finished the rough draft -- make any corrections right in the rough draft.