I just now tried to upload my portal in the linux server and after I uploaded everything including my data base and tried to see the home page I get the following error - Can you help me how to solve it.

Warning: mysql_connect() [function.mysql-connect]: Access denied for user 'bestjobs_user'@'localhost' (using password: YES) in /home/bestjobs/public_html/system_function_initialize.php on line 0

Warning: mysql_select_db(): supplied argument is not a valid MySQL-Link resource in /home/bestjobs/public_html/system_function_initialize.php on line 0
Access denied for user 'bestjobs_user'@'localhost' (using password: YES)

wishes

so you haven't got the persmiisons set correctly for that user/password
you need to define them correctly for MySQL to authenticate the user.

I don't fidn the security model used in MySQL particularly intuitive or understandable.

either set the permission using the command line client or consider using something like MySQL adminstrator. if you use the command line remember to flush privileges afterwards to make certain the server reloads the updated user profiles