Skiathos Town is the only town of note. Here you can visit the house of Alexander Papadiamantis, one of Greece's finest modern novelists. His Tales from a Greek Island is still a great description of Skiathos a century later.
Skiathos Town is a maze of cobbled streets, trailing bougainvillea, and red-tiled roofs. It is built on two hills, each of which has a 19th Century church: Trion Ierarchon and Panagia Limnia. There is good shopping and you may find antique shops with genuine folk artifacts.
A two hour walk from Skiathos Town on a well marked path leads to the small town Kastro. The town is now in ruins, except that eight of its original Byzantine churches still stand. (Christos has good frescoes.) Kastro has a good high view with a nice beach below. It's on the north coast, and like all of the north coast is subject to the meltemi winds, which can rage at times.
If you visit in high season you'd better prepare yourself for long lines and poor service. Skiathos has a huge pick-up scene and lots of night life. Some people love the scene on Skiathos, and some are looking for a quieter more authentic Greek experience. As you might guess, there are many bars. The bars aren't cheap, but they're plentiful. Some cater to particular crowds: The Admiral Benbow Inn attracts English tourists, while the Kazbar often fills with a mix of Aussies and Brits.
There are many eateries on the island, many with lovely views. The cuisine available ranges from tradional Greek to international choices such as Italian and even Swedish. Eateries geared to the tourist trade may be expensive.
See our Greece hotels for a complete look at accommodations available on this island.