Lyngsat is the best place I have seen to get information about what programming is available. However, its organization takes some getting used to.
The page linked above shows the programming that originates from the US but is broadcast around the world. Similar pages can be used to find programming originating from other countries. However, you need to understand what satellites are viewable from your location.
Other pages are those that show what's available from satellites you can see, such as: http://www.lyngsat.com/america...
This page shows the satellites that broadcast to the US, ranging from 61.5 W way over toward the east to 139 W way over toward the west. If you are located on the east coast, you may have trouble receiving 139 W unless you have a clear line of site toward the west and a perhaps larger-than-typical dish. Similarly, if you are located on the west coast, you may have trouble receiving 61.5 W. Satellites that are more directly overhead your particular longitude will typically be easier to receive. You can find your own longitude very easily by googling your zip code plus "longitude".
Once you're looking at a particular satellite, say Galaxy 19: http://www.lyngsat.com/Galaxy-...
then you need to understand the information that's presented. The first table lists frequencies in the ~4000 range, which corresponds to C-band. To receive these, you need a "BUD" (big ugly dish) of size 6-12 feet (2-4m). The next table lists frequencies in the ~12000 range, which corresponds to Ku-band. These can be received with a 30" (0.75m) dish.
The next columns to pay attention to are the provider name and the system encryption. Look for the "F" icon in the encryption column, indicating that the channel is FTA. Also confirm that the first entry for the transponder in question shows "DVB-S" (or "DVB-S2") and that this is compatible with the receiver you have. The first entry provides info about the multiplexed stream, whereas the subsequent entries provide info about each individual channel within the stream. A decent receiver will be able to figure out all these details itself, but older hardware requires programming in some details.
There's really a couple of ways to use FTA. One is to just set up a system locked to a given satellite and stick with a channel or small set of channels that are stable. The other way is to hop around different satellites and see what's available, since programming does change over time. For this, it's important that your receiver has "blind search" capability (which should be pretty common by now, but you should verify). Having the ability to program the channels easily with a computer program is another nice feature that many receivers offer. This can be a lot better than fiddling with the remote and endless menu layers. And, of course, a motorized dish mount makes it easier to change satellites.
A final word before you embark on this: Lots of these channels have online viewing options, which can be much less frustrating to view (or they can offer a different type of frustration). At least you won't have to fiddle outside with dish alignment on a rainy day to peak the signal. You can instead learn about proxies from the comfort of your desktop.