If you plan to start the manga, Chapter 245 onward is Shippuuden's storyline. Of course, if you're interested in the Kakashi Gaiden, then start from Chapter 239.

Besides the fact that Sasuke is taller, I don't really see much changes in his face. Sakura and Naruto does look older though. Naruto doesn't look as chubby anymore in Shippuuden. And Sakura's hair is spikier.