I'd like to learn more about programming secure websites
pierrefar: Depends what you mean by "secure": do you mean protecting against attacks or do you mean impenetrable transfer and storage of information?For protecting against attacks, the absolute rule is: Never trust anything that the user has provided. This includes form submission, URLs for requests (i.e. it could be a malformed URL), the HTTP headers, the cookies, etc. They are all vectors for an attack. The corollary to this is: validate everything. From here, you can start learning more about the creative ways your app can be exploited.For securely transferring and storing information, you'll need to look at encryption strategies like SSL and hashes (for, e.g., passwords) and the like.Of course we can only point you in the general direction. This is a very big topic!