configure user on virtual server

I have a virtual server, Debian Linux Configured and working fine, it works with PHP, Django [Python] I need to be able to create new users with SSH loging and ftp capability but restricted to only the www folder needed [chroot]. This is needed as the virtual server will host web applications where different freelancers will be working on, so I need to provide the freelancers with the ability to lo connect trough SSH, to do the necesary upload of files for the Django [Python], PHP web applications. Complete documentation of the process is needed. More tasks on the sys admin of this virtual server will be needed from right freelancer thanks!