you use #include like in all ANSI standard C/++ compilers. What I believe you have seen is "using namespace std". If so, that is also ANSI standard and acts somewhat like C#'s using, but if you have the MSDN disks , do a quick read through on the namespace references.
2) Do I include files using #include or 'using? Actually this whole concept is confusing me. If I want to use the standard C++ libraries, I've seen people use something like 'using std', but I assume I also have access to the .NET namespaces, right?