The Surveying the Agents of a Galaxy's Evolution (SAGE) survey covers the Large Magellanic Cloud (LMC; ~7deg×7deg) using the IRAC (3.6, 4.5, 5.8, and 8 mum) and MIPS (24, 70, and 160 mum) instruments on board the Spitzer Space Telescope. Three key science goals determined the coverage and depth of the survey. The detection of diffuse ISM with column densities >1.2×1021 H cm-2 permits detailed studies of dust processes in the ISM. SAGE's point-source sensitivity enables a complete census of newly formed stars with masses >3 Msolar that will determine the current star formation rate in the LMC. SAGE's detection of evolved stars with mass-loss rates >1×10-8 Msolar yr-1 will quantify the rate at which evolved stars inject mass into the ISM of the LMC. The observing strategy includes two epochs in 2005, separated by 3 months, that both mitigate instrumental artifacts and constrain source variability.