This advice is intended to help people who did not attend Clemson's undergraduate computer engineering program figure out what classes to take, and in general how to get started in the Computer Systems Architecture master's program.
Don't believe course descriptions. Talk to the professors. The course descriptions are usually inaccurate, and even within the confines of a single course, different professors will teach different material. Additionally, talking to professors is rarely painful. Professors are much more interested in you (partially because they may be able to get you to do work for them) than undergraduates, and it's useful to build some good relationships here for future interaction. A quick email asking about the syllabus is a good start.
My advice on course prerequisites? Don't bother. For an alternative perspective, here is someone else's opinion. Most Clemson courses list several prerequisties, but if they aren't at least graduate level class (600+), don't even consider it. Even if they are 600 level classes you are probably safe (800 level prerequisites are another matter). Which is not to say you won't have to work. You will, but this is more time efficient, and much less expensive -- remember, you could be out in the world making real money. There is another, less obvious benefit in avoiding 600 level classes. In 800 level classes you'll spend time with just graduate students, and since the material is harder, you will all commiserate together. It's important to get involved in the department, and the department is mainly graduate students. Admission corequisites are a different matter. They are required (I had to take ECE 329), and advice on when to schedule them is offered below.
When choosing classes for your first semester, it's important to note that every class is not offered every year, or even ever. Additionally, the class requirements are out of date, and there are several substitutions available that are not listed. The most important of these is the ECE 629 can replace ECE 842 or ECE 851 (i.e. you just need 2 out of the 3). The other big replacement is ECE 848 for ECE 845. More about ECE 848 later. The final point is, and all the literature is very unclear on this point, sign up for research hours every semester. More than 6 hours of research is fine, you just don't put it on your GS-2. Always take at least 12 hours, which usually means padding 2 - 3 hours of ECE 892 (research) every semester.
In your first semester, you should take ECE 629, the computer architecture class. If it's clearly material you've already had, skip it, but you're going to have to take a class your second spring semester. Not a tragedy, but the flexibility of not having to take a class is preferable. I took ECE 852 (Software Engineering) first semester as well, I don't suggest that. It's not any good, and it's not going to help you get attached to a research project. You should instead sign up for 2 additional classes taught by 2 different professors. Walt, my advisor, teaches ECE 693, which is a parallel programming class and ECE 873, a parallel algortihms course. Either of those is a good way to find out if you're at all into parallel computing. Otherwise look for a class by Dr Hoover or Dr Birchfield (800 level classes are more interesting -- they are also more work). Don't take your ECE 329 corequisite this semester if it's required. Or at least don't take it from Dr Reid (if Dr Ligon is teaching, go right ahead and take it, you'll at least be developing a rapport with him).
Your second semester is much more regimented, you will have to take ECE 848, which replaces ECE 845 on the course requirements. You will also need to take ECE 842 or ECE 851, whichever is offered. For your final class, you'll probably need another 800 level class, or this is the time to fill the ECE 329 corequisite if you have it. Either way, 848 will be the hardest class you'll take. Dr Russell is a great teacher, but the material is just plain hard. Still, I knew virtually no probability when I took it, and I made an A. You can too, just plan to mainly do coursework this semester. No one gets any real research work done during this semester, and no one expects you to. Give an honest effort, and don't fall into the self pity trap -- it's easy to do, because many of your classmates will be in full whine -- this may be the first time that they or you ever had to work for a grade.
That takes care of the coursework for the first year. By the end of your first semester you need to have spoken with all the professors about their research individually, and have made some tentative plans. In your second semester, you start going to a project's meetings, and every week you need to try to report a status item at the meeting. You won't be getting much done, but remember, everyone knows what 848 is like for the Architecture guys -- even the Wireless students get crushed in that class. Do the best you can, always try to show up to status meetings with at least one item to give an update on.