There are good tutorials to Haskell, but it seems to me that Haskell best practices still evolves fairly quickly. After "Real World Haskell" and "Learn you a Ha

There are good tutorials to Haskell, but it seems to me that Haskell best practices still evolves fairly quickly. After "Real World Haskell" and "Learn you a Haskell", I still did not know what most of the GHC extensions are for (especially those related to generalizing types seem interesting), how to write idiomatic IO-code (conduits now, apparently? Or is it Pipes?), or how I should choose between the many ways of computing on many cores. Is Data Parallel Haskell mature enough? STM? The par combinator? accelerate? I don't think they mention Template Haskell (which seems powerful). The recommended way to connect to SQL is also in a state of flux (possibly "persistent"?).