Detailed information on how to get to the city of Lviv you can easily find on the LVIV.TRAVEL, the official city travel site.

By air
Airport Address: 168 Lubinska str.
Information: +38 (032) 229-81-12 (free), 240 (chargeable)

By rail
Train Station Address: 1 Dvirtseva sq.
Phone: +38 (032) 226-20-68, 1505 (Reference)
You can buy tickets online using the official booking service of Ukrainian Railways.

By car
If you travel to Lviv by your own car, it will be best for you to follow E-40 International Highway (from the western border to Lviv it is M-11 Ukrainian Highway, and from Kyiv it is M-06).

By bus
Many regular bus routes in Western Ukraine (both direct or transit) run to Lviv from virtually every city, town or village.
Bus schedule is available here. You can book bus tickets online using TicketsUA service.