Using System.IO for Diary?

Hi there, i did try searching but i need abit more explanation on how to do this, i've seen that to do this i would require system.io. Although i don't think that sort of method is any good for the span im going for, i wish to make an diary application but read / write to textfile or XML? from a webserver, because of the amount of different pages i will need to be saving.

The problem im facing is working out how to not only write to each page, but to organize and "read" them in an orderly fashion (by date, by title etc.)

if anyone could point me in the right direction or link me up with some examples then that would be great!

Thank you for taking the time in reading my question, if you need any more details then i can explain more.