如何显示用户首次登录的教程/信息？

I am building a social network site, and I am wondering how can I display a interactive tutorial and information on users first login. Such as only on the first login, users are asked to fill more information on their profile . How can I achieve this though php and mysql? Example:

When a user signs up to your website, you can add a field which stores the date of their last login. When that field is still NULL for example - it's their first login.

You could achieve this by simply adding a column to your userprefs table (or whatever you use to store your user-specific settings), with a boolean/int defining whether they've completed the tutorial.

Upon completion (or when the user clicks Dismiss), you set the value for that user to true/1.