There are many ways to go to Wroclaw. The city counts with its own airport, which will actually be expanded as an investment for the UEFA EURO 2012, together with the construction of a new and modern terminal. You can find cheap flights with companies such as Wizz Air, LOT and Ryanair, so it's a metter of researching. In advance is always better if possible.
Another way that can suit you is to go by rail. The Polish trains are not the most modern or faster, but there are some cheap and confortable options when looking directly to the Polish Rail (PKP) timetable and fares. All the trains I got so far have the classic cabins, and if your are lucky you can have most of it for yourself! It has been also a surprisingly good way to travel as I have headaches while reading on buses but not on trains. There are some direct trains to other turistic Polish cities, but it is not so easy to find them if you want to come from or go abroad.
Then probably is better to look the bus companies. Although you can not streach your legs and walk as in the trains, some trips are much less expensive and faster to go by bus then train, besides the fact that may be easier to find direct buses then trains to the countries nearby. There are many options to look at, all I have seen providing wi-fii during the trip, which does not always work on its best but is definitly a convenient service.
And then, of course, you can go by car. Although I read many bad reviews about the conditions of the roads, haven't really travelled through a bad one, even though they were all one lane roads. Maybe it was my luck. Anyways, it seams a good option if you want more privacity, make your own schedule; and adventures, many would say.
Once you made to Wroclaw, it is pretty easy to get around. The city has a good and cheap public sistem that includes trams, trains and buses. Especially the trams and buses can take you everywhere for a good price, as it takes only 1,20 zlots to get discount tickets (for students, senior and kids), which can be purchased at the machines located in some stops and inside the vehicles. The difference is that inside them you can only pay by card, but in both machines you have the option of getting up to ten tickets.
But there is almost no need to take transportation. Most of the city attractions are close from each other, so it's sometimes even faster to walk or ride a bike to get to the places you want then waiting for the right tram to be there. The geography also helps to save energy, as Wroclaw is incredibly flat. Besides, walking is the easiest way to actually look at the details of the streets and buildings, see what polish people do and where they usually go to, and simply really experience your stay.
As for the bikes, there are some places you can rent them, as at the tourist information center at Rynet (Market Square), and in many of the hotels and hostels around. But since this summer, the cheapest way to rent one is to use the Wroclaw's Urban Bike system. You have to register online first, which costs 1zlot, and then it is just find a pick up station to start biking. There are 23 of them, the most popular being at Uniwersytecki Square, Market Hall, Galeria Dominikańska, Market Square or Bema Square, and the 20 first minutes are free of charge. After that, it costs 2 zlots for an hour, and 4 zlots for each additional hour. The only thing is that the cycle paths are not so developed, because riding a bike is not such a common thing to do, even though you always cross with a cycler here and other there ...
And of course, if you are looking for a more privet transport, there are the two classical options: renting a car or taking a cab. Taxies are expensive everywhere, but there's also the classical tip of calling one instead of catching at the street, which can save you from 5 to 30% of the fare. The car rental is also not the cheapest way to go around, and will give you some work to drive around the main areas, as those are old streets. But the service is available at the airport and in a few other locations closer to downtown.
My advice?? Get a free map at the information center and start walking .. hopefully with a beautiful sun to make life prettier!! And with the good weather, enjoy a ride to some park, like the Szczytnicki Park.
Additional info:
You can also use the so called mobile eco tourist, a small car/cart that offers guided tours, which are easily found in all the Rynek corners. And to go along the Odra River, there are also boat trips available! Those you can take from the harbour situated by Bulwar Włostowica on Piaskowa Island.
Good website to check public transportation routes - http://wroclaw.jakdojade.pl/ - remember to search with the original polish names!!