standard file loading function and a for loop?
What do you mean by that?
The way to go with C++ is a fstream.
But depending on what the data is used for you might want to jump through the file instead of loading every byte into memoy.
Questions like, what is the best way to do X, are mostly bad questions, since it always depends on what you're doing, how large the data is, what PC specs you're developing for etc. -> provide more info