Just one day to gather roles and responsibilities ? Well, there are good posts to go by and lots of information out on the web. I'd really think twice though before committing ... depending on ...
1) the size of your organization
2) the number of servers
3) number and types of applications
4) network and OS support
5) SLA's (Service Level Agreements) for network, OS, Applications & SQL Server
Senior Database Administrator
"Ave Caesar! - Morituri te salutamus."