Ever since I started learning Latin, I had a question: how did the Romans pronounce Latin? Not the word, but the language in general. To make it easier for you to answer, please compare their pronunciation to that of a modern civilisation.
Instead of giving a pronunciation guide here, let me point you to some resources that should get you started. The topic is very broad and I doubt I could give sufficient instructions within an answer of reasonable length.
First, let me point out that we know fairly well how the Romans pronounced Latin. Many present-day Latinists, including myself, try to pronounce Latin as the ancient Romans did.
I suggest taking a look at our pronunciation resource list. To get an idea of the classical pronunciation, I recommend listening to the Latin news broadcast Nuntii Latini. My understanding is that the pronunciation used there reproduces imperial Roman pronunciation quite accurately. Seeing the text and listening to the audio at the same time should quickly give you an idea of how it works. The only missing thing is macrons; vowel length is rarely indicated in writing but is needed for accurate pronunciation. A good dictionary and grammar should be able to provide you with the macrons.
Wikipedia has an extensive article on Latin pronunciation and spelling, and that will give you a number of details regarding classical pronunciation and differences to later pronunciation. Beware that Latin pronunciation is very non-uniform; people from different areas will have wildly different pronunciations, and that has been the case for centuries.