how to create a new forum in drupal 5?

i would like to know how i can make a new module in drupal , the tutorial sources is kind of confusing for me and i get lost ,can any one help me on this issue?
i need to sort a list of categories in my website ... meaning that users can sort the categories according to their interests like ;

user 1
1.sport
2.movies
3.activities
4.holiday
5.mobile

user 2
1.movies
2.mobile
3.holiday
4.activities
5.sport

user3
...