I'm taking a course on relativity, both special and general. According to my college, I have the required mathematical background (vector analysis, electromagnetics (though I can't recall more than a cursory glance at tensors) etc) to make sense of it. Special relativity I can handle, and I think I understand the general concepts of GR fairly well, but how to actually do the math eludes me. The book I have is Ta-Pei Cheng's Relativity, Gravitation and Cosmology. It does an OK job of explaining the theory, but it tends to not do the calculations, instead calling them 'straight forward'. Math has, sadly, never came that naturally to me, and I don't follow. So what I need would be a guide to the mathematical framework, one that spells it all out explicitly. Does anyone have any recommendations?