Question : Process to perform general user administration in windows environment

What is the processes typically small and mid-size companies follow to provide general user administration within the Windows environment to address the following items:
1. User creation/destruction/management
2. Manage domain controllers (login scripts, profiles, etc.)
3. Manage security restrictions and network access for users

Any guidance would be greatly appreciated.

Thank You

Answer : Process to perform general user administration in windows environment

Quite a big question. What level of depth are you looking for?
Documenting everything so an organisation isn't completely reliant on one person.
Network drives with differing security settings are also essential.
Strong back up routines are also a must.