In case you are looking for practice tests for either the MTA exams or the MOS exams, I discovered the following site:
I paid $70 for the entire Office 2010 Suite, including Word & Excel EXPERT level tests, and I think I have a few years before it expires. I haven't looked at the MTA tests yet but the MOS practice tests are EXCELLENT. These are not those
multiple choice exams, they actually simulate the real exam.