Webhosting
You can host your personal webpage or files at Blinkenshell.org. To do this, put any files you want accessable via HTTP in the directory public_html in your home directory.
If you have a file named index.html or index.php that file will be used as the index page when someone browses to your site without specifying a specific file (ie http://user.blinkenshell.org/ ) If you do not have an index file a directory listing of all the files in your public_html will be shown instead.
You can use apache .htaccess-files to customize the behaviour of your webpage. Apache documentation on htaccess.
You can use PHP for your webpage. PHP is configured with su_php which will make all scripts execute as your user permissions instead of the apache user. Also, suhosin is enabled to further increase security. For security reasons, all your php files must not be writeable by "group" or "others".
CGI is enabled in ~/public_html/cgi-bin and executed with suexec. Again, permissions are important here. The script has to be executable by your user, and it must not be writeable by "group" or "others".
The URL to your webpage is: http://username.blinkenshell.org/ (http://titan.blinkenshell.org/~username/ and http://blinkenshell.org/titan/~username/ also works. The last one is the most real, the others are done with mod_rewrite magic.)
Proxy
All requests to your webpage are handled by Apache on the shell server. However, the requests are proxied by a Reverse Proxy on the way. This might cause some problems, especially with PHP or CGI scripts that doesn't take this into account.
A common failure is to not properly figuring out what URL to redirect after submitting a form. This is because there is no way for the script to know what URL the user should enter to access the script, since it's being rewritten by the proxying server. This is often solved by specifying a "base URL" or "absolute URL" or something similar in the script configuration file and force it use this instead of trying to figure out the URL on it's own.
Also, if you want to get the IP of a visitor you can not use the normal way since you will only get the IP of the forwarding proxy. Instead use the data available in the X-Forwarded-For request header (More about X-headers in Apache's Documentation.) This data is available in the variable $_SERVER['HTTP_X_FORWARDED_FOR'] in PHP (this variable can contain multiple IPs.)
MySQL
For information on how to use MySQL, see: Info/MySQL. Remember to connect to host 192.168.0.1 and not localhost.