How to store Employee's working history ?

Hi gurus,

At present I've a problem with storing employee information for the following :

1. Working history for an employee ( At our company ) , For example :

The employee has joined in how many projects , Time , Positions.......

(How can I store these infomations ?)

2.Employment hostory , Experiences : Before entering our company ,The employees have worked in various Company under many positions, So how can I store these information ( In which Infotype ...etc, Is it neccessary for creating new ones ???)

Thanks...