What is an optimal reading order for a set of related papers? A common problem I encounter every time I do a literature search on a new subject is determining a reading order for papers.  It feels akin to jumping into a prolific sci-fi fantasy series, but since there usually don't exist enthusiastic fan bases for a random subset of papers on numerical methods for PDEs, I'm always struggling to figure out how to get started.  My default is chronological order (oldest to newest), but this frequently poses problems if the oldest paper is using outdated notation or technology.  A newest to oldest reading order has the problem that it might assume background information from previous papers, which leaves me feeling like I have to keep jumping around texts and never really get a coherent picture of any of them.

Does anyone have better ideas for determining an "optimal" reading order for related academic papers?  Perhaps a simple metric for ranking importance (but not citation counts, since this would skew towards older papers).

Note that when I say ``read a paper," I'm already employing a multi-stage technique where I read the abstract, conclusion, and introduction, then skim the text, and afterwards decide whether it's worth downloading and reading in detail. So the set of papers I have now, I've determined are worth really reading in detail.
I often struggle with the same question.  One approach which I find often gives good results is to start by skimming through all the papers (typically in chronological order) and use this first reading to decide on a more appropriate reading order, typically starting with the ones which seem more introductory or survey-like and ending with the more detailed ones.