Riga International Airport (http://www.riga-airport.com/) has direct flights to/from various European cities London, Madrid, Frankfurt, Amsterdam, Barcelona, Oslo, etc, Middle East Beirut, Tel Aviv, Dubai, CIS Moscow, Kiev, Minsk as well as North America New York City.
Inexpensive national airline: Air Baltic (http://www.airbaltic.com/). There are also other low-cost carriers: Ryanair (http://www.ryanair.com/) and WizzAir (http://www.WizzAir.com/). You can take also Ryanair (http://www.ryanair.com/) flight to Kaunas in Lithuania but it might be not so easy to get from Kaunas to Riga by public transport.
There are bus nr 22 0.70 LVL and taxi <10 LVL connections to city centre. Red taxis (http://www.rtp.lv/eng/ind...) operate from the airport to the city center. The green Baltic Taxi operates from the airport to the city center for a flat fee of 9 LVL if purchasing a voucher from the Baltic Taxi booth inside the airport; the same voucher costs 8 LVL if purchased from flight attendants on board an Air Baltic flight credit cards accepted. Journey times depend on traffic. Airport operates 24h hours.
If departing in the morning, allow yourself plenty of time to proceed through passport control as it can get crowded.
Major "Via Baltica" road links Warsaw, Poland through Kaunas, Lithuania, crosses Riga, Latvia and goes to Tallinn, Estonia. If you have a driver's licence issued by another country of the European Union, you can use it continuosly. Residents of other countries have to obtain a Latvian licence after 6 months; however, it involves only a theoretical exam, which can be taken in English, German, French and Russian.