Your best bet for this kind of material is to visit www.cramsession.com and check out their various downloadable study guides (in PDF format). You will also find lots of good, relevant information at www.microsoft.com/technet/, www.certcities.com, www.itcertinfo.com, and by using your favorite search engine to look for materials on specific topics. But alas, I know of no sites online that specialize in providing free downloadable e-books to help people prepare for the MCSE. Most content providers seem to want to get paid for this kind of thing.
This was first published in July 2002