The National Trust for Scotland visitor centre sits near the head of the glen and covers both the natural history of the valley and the story of the 1692 massacre. It is a good starting point for anyone unfamiliar with the area — the maps and route information are particularly useful for planning walks. The centre has a café and toilets, making it a practical stopping point even if you don't linger inside.
Glencoe Visitor Centre
NTS centre covering glen ecology and the 1692 massacre