[plt-scheme] Read and Write from file

Hi to all, I'm a student developing a game (as project) and I need to read and write a file.. I just want to load some integers and symbols from a file to a struct, then to save the struct as integers and symbols in the file back again..

The file content should be something like:

'hi
1
2
3
'bye

I haven't found a lot about read and write... I mean nothing that I can understand.
I think I should use the "send" function but the help about it it's soooo hard to understand.. Can someone tell me where I can found some examples?

Thanx for your time :)