Having moved from CPH/MMX to HEL a few years ago I though I'd share some hints. If you would like to add/correct just post a reply and I'll update this post. Terminals & lounges The airport is divided in two terminals T1 and T2. Generally Finnair and their partners use T2 and SK + all others use T1, exact details can be found here. There is a both an airside and landside walkway between the terminals, the walk will take 5-10 minutes. If you are on a long layover I suggest spending it in T2 as both the view and facilities are better. T1 is generally more crowded and with less restaurants/shops.The only lounge in T1 is the SAS-lounge. In T2 Finnair has their lounges and there is a general lounge for other airlines (no Diners-access). Ground transportation City bus 615 (any letters at the end is ok) is the cheapest option, travel time about 40-45 minutes. You can get on and off at all stops in Helsinki (not Vantaa). Price is €4 and you can either buy with card/cash at the machine at the stop or cash to the driver. I would recommend this option unless you are travelling with a lot of luggage. Finnair-bus is faster than the city bus but also more expensive, travel time about 35 minutes. Price is €5,90 and you pay with credit card to the driver. Travelling to the city you can get off at all stops it passes but travelling from the city it will stop only at the central railway station and outside Crowne Plaza/Scandic Continental (Töölö). Shared shuttles are available and do not have to be pre-ordered when arriving. The most common is Yellow line. If you are not travelling alone getting a private taxi may be cheaper. There is a taxi-line outside arrivals, price depends on how many travellers you are (1-2, 3-4 or more). All taxi fares are regulated by the government so it doesn't matter what taxi you get in to. Expect to pay up to €40 for 1-2 people to Helsinki city centre. A railway is supposedly coming this lifetime but until then you are stuck with travelling on the road there. Travelling to other cities. There are long-distance buses stopping at the airport or you can take bus 61 to Tikkurila where all long-distance train stops. Long layover If you are on a long layover and can't get into any lounge the most quiet place is between T1 & T2. Though the chairs may not be that comfortable there are usually less people around the gates in this area.With a bit more time on your hands you can visit the aviation-museum which is open daily. You can get there by almost any city-bus departing from the airport but in the summer-time it is also walkable in about 20-30 minutes.Should you want to take a look at Helsinki take the bus to the central railway station and get on tram 3B or 3T (the same line, just different direction). This tram-line does kind of a scenic tour around Helsinki and you can get on/off at any stop. A brochure can be found here.