Don't roll any class just because people tell you to. Try a few out and pick the one that you enjoy best. It's your toon not theirs, so make sure you enjoy the class.
Honestly, if you don't enjoy healing don't roll a priest. This is the main question you should ask yourself. Even as a shadow priest you'll be healing in most instances until you hit 70 and start seeing a lot more holy pallys and resto druids. At that point the demand for shadow priests actually skyrockets but until then you'll be doing a lot of healing so make sure you are ok with that before rolling a priest.
As for races. again my advice is simple. Pick the race you like the look of the best, you'll be looking at this toon for a long time so make sure you like the "feel" of the character. The only race that has a real edge on the others is draeni who get an extra heal over time racial and mana regeneration racial.
As for builds, almost everyone will recommend shadow. Priests really have 1 good talent tree (shadow) and two mediocre ones (holy and discipline). Most players chose shadow for ease of leveling/soloing. To get more specifics look at the Shadow Priest FAQ at the top of the forum index.
Good luck :]
Edited, May 4th 2007 3:18am by MookusOU