Form to file?

Hello everyone… for a shool work i was asked to make a form where a user would put in some personal info, and then that info would be put into a file that could be read into a program like exel or something like that. The person that ask me about it did not went into details so thats all i can say about it. Does anyone know a good way to do this? also where can i find some good tuts about that sort ot things?? thanks in advance!!