SCO's ACE certification program requires passing a series of tests to demonstrate proficiency in SCO operating systems and Unix in general. The exams aren't overly hard, but do require a solid base of knowledge and good preparation.
SCO has sample questions (link above) that will show you the general areas the tests cover. It is very important that you review these so that you understand the extent of the tests.
My questions are not really designed to help you with the SCO ACE certification exams, but you still may find them useful for helping you understand areas where you may be weak. There are some relatively tough and obscure questions on the ACE tests, so don't venture in thinking that it is all as easy as their sample tests questions might indicate.
However, if you know SCO, or even if you just know some other SysV Unix very well, you shouldn't have any real problems. There are, of course, SCO specific questions, so you should at least have some familiarity with the SCO administration tools, but a lot of the questions would apply just as well to Solaris, for example.
If you do not understand shell programming, you will need to bone up on that, and there are some tricky questions in that area. I found the uucp questions particularly challenging just because I haven't done much uucp for many years.
SCO has a new certification option that requires only one test. The link above has complete information.