Annibale:
Do you have a scanner? To open a scanned negative or slide in photoshop go to File, then down to Import, then go to your scanner. Once you scan the negative you can import it to PS and take it from there. I find I get great results shooting Ilford XP2 which is not a true B&W silver halide film but scans very well. Like others have indicated, books, tutorials, and I would add, trial and error, and consulting is the way to go.
Cheers,
Wilfredo
Benitez-Rivera Photography