"bit puzzled as to how i can implement the users database that will contain users posts, and comments made about the posts. "

Your user table should be something like:

Table users:
user_id (PK, auto_increment)
username
user_password
email
....
"My current idea is to have individual tables for each user and store their data in there" - I don't think is such a good idea.

Posts table:
post_id (PK, auto_increment)
user_id (FK, index)
post_title
post_content
post_date (date_time, index)
//....

Comments:
comment_id(PK, auto_increment)
post_id (FK, index)
user_id (index) #the user who inserts the comment, if anyone can post comments, ignore it
comment_date (date_time, index)
comment_content

Now, if you will have a large database (milions of posts and comments), extra optimization should be added. For that post later, or check phpBB db design...