I don’t have any idea yet, but I have my set of how to. Especially this talks about screen resolution. Getting from the statistic and all that, may not be that much accurate nowadays, because those general statistic is not YOUR statistic. So I tend to skip that part, and look into the existing statistic.
Most of my sites are 1280×800 resolution above. A very very common screen resolution today. A 14″ – 15″ laptop 16:10 ratio should be this resolution. Well, to be honest, who look at the height (800)? So we can skim the rest ratio for the same size laptop.
That being said, 1280 is the most commonly used resolution. 1024 used to be the common one, but it is still the common one, for netbook. So I can’t really skip this resolution. The rest, well, responsive is here to save the World 
I divided it into 3 groups, mobile, tablet and desktop.
So all there need is both fixed and fluid layout to work around all those sizes.
So my questions comes along too. With the statistic that keep telling me that mobile users will be keep raising the bar, and laptop/netbook are going to replace desktop computer. Am I the one who question the weight of the sidebar information? A website with sidebar information and some 3 columns footer for example. So when it shrink into mobile size, what is to do with the 3 columns and some sidebar information? Are we still keep pushing information toward users even in small screen? Hmm…