Hello my name is Nikolaos and I can help you with your problem. I'm an experienced back-end and front-end developer. A sample of my work may be seen in my portfolio.
1st
sending email is very easy to do with the php function bool mail ( string $to , string $subject , string $message [, string $additional_headers [, string $additional_parameters ]] ).
2nd
I would suggetst using SHA1 instead of MD5. There are devastating collision attacks on MD5.
3rd
For the reset/forgot password it is more safe to reproduce a random temporay password using SHA1 and email it to the user. Then the user after accesing his account via the temporary password can reset it to whatever he wants.
I'm willing to screen stream you the whole procedure step by step in order to better understand.
For more information and details please do not hesitate to contact me anytime and any hour.