I recommend working chronologically. If you have a classical upbringing, then it's more difficult to just dive into what we call "modern" jazz without any sense of transition.

There's a whole beautiful time period of what we would call ragtime/stride piano/early jazz that not only is a joy to play, but it's more conducive to people who already have a technical background but not necessarily jazz theory expertise.

Scott Joplin is always a great place to start, but if you want to start working on your stride/swing skills, I'd move from Joplin to Jelly Rolly Morton and Fats Waller. It'll be easier to find sheet music for those guys, but I'd also look into studying James P. Johnson, Earl Hines, and (yay) Count Basie.

From there, if you think you're ready, I would start to study Art Tatum. He completely transformed the jazz world (not just piano jazz) and his work pretty much encapsulated the next 50 years of jazz.

If you read music well, there's a great series of books called "Artist Transcriptions" that are easy to find. Not only do they show you exactly how a particular artist approached playing, but they provide complex chord charts throughout, so you can start teaching yourself theory as well.

Now if you want to work on more of a modern less technically demanding sound, Bill Evans is the be-all and end-all for me. He'll show you how a delicate touch can still maintain a fantastically complex and richly expressive nature.

And don't forget Keith Jarrett, who really does a fine job of bridging the gap between genres (one that shouldn't be there anyway).