Configure ZyWall 100 USG

Hi,

We have a  zywall 100USG installaed, how do I add users(not licences) to the device?

I would like the users to gain access to our corp network by using a vpn connection shredsoft or the windows vpn connection.

I'd appriciate a step by step guide.

Where is this configured?

I would like to provide our users with a username and pass to that they can access our network from home.

Thanks