Nangan is an island in the Matsu region of Taiwan.It is the primary and governing island for the Matsu Islands. It is also the largest of the islands. Most flights and boats will fly into Nangan. There are many things to see and most signs are in English, albeit some travelling requires guess and test.
The capital and location of the airport is Jieshou Village(Shanlong). Nioujiao Village (Fuxing), Fuao Village, Matsu Village, and Renai Village marks the other main villages. They are all tied to Central Blvd one way or another.
Since Nangan is the main island, there is massive military presence on all corners of the island. China is only a few miles off the coast and quite easy to see on a clear day. Nangan is also the main island, so travelling between islands is mainly via Nangan.
Also do not fear the roads. It may look like a sidewalk, but it is probably a road.
You can either fly using Uniair or take a boat from Keelung.
The Taima (臺馬) ferry from Keelung takes between eight and ten hours and docks at Nangan (南竿) and Dongyin and runs every day except Tuesday, weather permitting. From the Keelung TRA station, turn left and walk about a block along the harbor to the ferry terminal. The boat leaves Keelung around 9 p.m. and arrives early the next morning. Economy bunks are inexpensive and relatively comfortable -- in addition to safe even for solo travelers -- but private rooms sleeping two or four in bunks or a double bed are available in business and first classes. Online reservations are available, but the system only allows you to make reservations for specific days, so start checking seven days prior to travel and check back often. To avoid lines, reservations are recommended whether using the online system, phone, or in-person booking at the terminal. However seats -- and even bunks -- may be available the day of travel, but plan on arriving at the terminal 2 to 2.5 hours before sailing. Regardless, as weather frequently cancels trips, payment is not made until the day of travel. The return passage departs Nangan around 9 a.m., and tickets can be purchased from the ferry station. As of June 2015 construction was underway of a new ferry terminal,but the ticket counters are located behind the strip containing the 7-11 and ferry ticket booths for the local ferries. Look for a two-story building with gold lettering.
Uniair has approximately seven daily flights between Taipei Songshan Airport (TSA) and Nangan and one to Taichung (June 2015). The flight is one hour long and tickets can be purchased inexpensively the day or so before travel.
Whether traveling by air or sea, be aware that weather frequently cancels flights and cruises with little warning, potentially leaving travelers stranded on the island. While accommodations are relatively plentiful, plan for the possibility of an extra day in Matsu.
It is highly recommended you rent a scooter from the airport or Fuao harbor. Go to the Visitor Information and ask for help.
Also do pickup the English Backpackers Guide. It has highly detailed itineraries and somehow manages to provide an incredibly useful map.