Please help me with these questions..

Hi all.. I'm a beginner in PHP.. And I'm working on a project.. I want your help please to learn how to : 1- MD5 with PHP values. 2- Random values in PHP. 3- Inserting values to mySQL DB by PHP and importing from them also to send echo. (For example : after MD5 some strings in PHP I want to insert them into the database also then to echo these MD5 strings). 4- How to echo something. 5- How to make some GET values like : http://www.mysitename.com/test.php?username=abc then insert them to the database. Hope some experts help me with these.. I want to find some tutorials about them...also some examples.. Waiting your replies.. Cheers and regards.. Hadi Aladdin