Read them all...in chronological order or jump right to THE MURDER OF ROGER ACKROYD. Also check out the DVDs of the Masterpiece Theatre productions. David Suchet, a Brit, does a masterful job as Hercule and there is an ORIENT EXPRESS, plus a movie version w. Albert Finney, I think, but not as good. Then go on to the JANE MARPLE series, also on MT.