If you are going down the Microsoft Cert route its worth looking at some of their e-learning courses. Loads of them are free and the development ones are pretty good. They will give you an idea of the way the exams work too (memorising phrases from the books by the look of it)
Microsoft Learning Manager - English Catalog, E-Learning
Is the link sorted by price
Microsoft Learning Manager - English Catalog, E-Learning, Microsoft Certifications, Microsoft Certified Desktop Support Technician (MCDST)
Is the desktop support courses. There is a free one on preparing to do the MCDST which might be worth doing