The textbook for this class is Computer Organization and Design, the Hardware/Software Interface, 3rd edition, by David Patterson and John Hennessy. Patterson (past president of the Association for Computing Machinery) and Hennessy (president of Stanford University) are very big names in computer architecture, and they are excellent writers to boot. Read the book. It's worth your time.
Your grade in the course will be determined by your performance on two takehome midterm exams, a takehome final exam, and homework. Each of these four pieces will count for 25% of your grade.
Working with your classmates is generally a good thing. Sharing insights can be fun, and can enhance everybody's learning. The main danger of collaborating on course work is in allowing your collaborator to do all the work, and thus all the learning. If you want to work together on homework for this class, that's fine with me, but take care not to fall into collaboration's traps.
For programming assignments in this class, you may work alone or with one other person. If you work with a partner, you may submit one copy of the code with both names in the comments.
For all other assignments, you may work with others, but should write up your answers individually.
For takehome exams, you must work alone, using only the resources I explicitly allow.
If you have any doubts about what constitutes acceptable collaboration, let me know.