Calling an API

I am trying to use an API that I found (it is written in C++). I am trying to call the API from some C++ code that I'm writing. I tried including the API header files in my program, but I'm getting compilation errors. I'm guessing this is probably a pretty common thing when trying to use an API. I am not really experienced in including & calling someone else's API when writing a program. I am looking for someone who is more experienced in this area to help me figure out how to get this working. To be clear: the goal of this project is simply to get a simple "hello world" program working that can simply call functions in the API, nothing more complicated than that. (right now i can't get anything to compile when I include this API, so the tough thing is the compilation. once it's compiling, there shouldn't really be anything else to deal with!) Additional Info: I am working in Linux using gcc/g++ (not using an IDE such as Eclipse or anything, just raw makefiles)