Maybe start with Miles' "Sketches of Spain" record. It seems to be one of his most accessible. That, or "Birth of the Cool". One of his best works is a soundtrack for the film "Ascenseur pour l'échafaud". The sountrack is pretty hard to find so if you see it, grab it. If you dig those, dive right into "Kind of Blue". It's one of the greatest albums ever recorded. Dig that, go as deep as you can into his amazing catalogue of music, especially the electric era. Check out the "In a Silent Way", "Bitches Brew" (especially this one)" and "On the Corner" albums to have your mind blown. As stated before in the thread, try out the later era Miles if you got into the earlier stuff first. It's not for everybody obviously but if you appreciate the other recordins you just might love it.
You really can't go wrong with the 5 kings of jazz. Miles, Coltrane ("A Love Supreme" is essential), Parker, Ellington and Monk. Sun Ra is another great but a lot of his stuff is really out there like later era Miles so check him out if you find you like the more avant garde jazz. Oh, and Charles Gayle! New York sax master.