This is a seven hour walk, and not a great one for people with fear of heights or too-heavy backpacks. A good trekking map will help you find your way with this route. Samarina is said to be the highest village in Greece, at 1450 meters/4756 feet. In summer Vlachs come here from the Thessalian plain with some 50,000 of their sheep. The village has few inhabitants in winter. It was burned during both WWII and the Greek Civil War and was built fast and cheaply without much regard for tradition or beauty, so the only good reason to come here is to enjoy the friendly people, who are the proud bearers of Vlach tradition.
This is one of the places in Greece with a big celebration of Dhekapendavgousto (literally, 15 August), which is the Feast of the Assumption. Music and dancing (and food and drink of course) are what's happening then, with Vlachs from all over Greece returning to their roots for this paneyiri.
The main church here, which, being the church of the Panayia (Virgin), is the cause for this saint's day celebration, is quite impressive, with painted ceilings, frescoes, and a finely carved 'temblon', where the angels, soldiers, and biblical figures have big mustaches and are dressed in fustanellas (the traditional white pleated Greek kilt-like skirt worn by men). This church, like many others in the area, seems much older than it is (from around 1800). A black pine tree grows out of the roof of the apse. If you want to go in and look around, find the pappas (Orthodox priest) who lives across from the church's main gate.
Lodgings in this town being rather expensive, camping in the pastures outside of town is a very good choice (and is tolerated).
Leaving Samarina, you can get a bus east 40km to Grevena (though not daily) between June and September; or you can hike the E6 trail to Dhistrato, and stay overnight to catch a bus to Konitsa, or keep going to Vovoussa on the east bank of the Aoos, which has less frequent buses to Ioannina.