Kiehl and Trenberth 1997 is a widely cited document on the Earth’s global, annual energy budget and discusses important things like how much solar radiation comes in, how much is reflected away, how much infrared goes out, how the surface energy budget is partitioned between radiative and the latent and sensible heat fluxes, etc. The authors (along with J. T. Fasullo) have a new, 2008 paper on the same subject—and a new colorful diagram to go along with it. These values are all globally and annually averaged, with the “net absorbed” part of 0.9 W/m2 due to the enhanced greenhouse effect.
Update— Actually it will be a 2009 paper, coming out in BAMS in March.
Climate Change 