You can also enter the country by boat from the different ports such as Poti and Batumi. The boats come from Odessa and Istanbul.
There are buses that take you to the city including normal buses and minibuses. Also, if you are driving make sure that you have your route planned ahead of time and that you have the route accessible in a few places. If you are using a GPS or your phone to give you directions make sure that you have access to the route on another device or an actual map. This is to ensure that you can still figure out where you are going if the GPS or the phone has some sort of malfunction.
There are numerous ways to reach this country including airways, bus, car, train and boat. The international airport is located in Tbilisi and is serviced by many of the larger cities in the world, including London, Paris, Vienna, Warsaw, Kiev, Munich, Athens, Riga, Istanbul, Prague, Minsk and many more cities. You should check with a travel agency or online to figure out the best and easiest way to get to the country from your location.