I started as an accidental DBA on MSSQL about 8 years ago, and I made a lot of the classic mistakes surrounding maintenance. Some of my mistakes led to time and data loss, easily prevented with an educated backup plan. I knew how to properly maintain Access and Foxpro, filesystems, and worked in the IT world, but didn't know MSSQL's particular way of doing things. It would have been ideal for me to go in with training, but the company at the time expected everything with zero investment (not even books). For 5 years I was "That SQL boy" and learned at my own pace, on my own dime ... nickle, really.
All that said, I think safety nets are good for business, good for the product image, but should not always be defaulted on. The installer shouldn't have to ask 20 questions to determine if this is a personal install or mission-critical cluster, but if it can offer a maintenance setup page with very few defaults enabled, that would help the novices.
It's common for someone without experience to run out of space on the backup drive and have transaction logs fill up, or worse yet not have a backup in the first place. OK, maybe the worst is backing up to the data drive.
Back in the Windows 3.1 days we had printed manuals to flip through, with basic starting instructions. Software was easier back then because computers didn't do as much. I forget - does the SQL08 installer have any form of "Welcome to SQL, here are your first steps" documentation readily available? Is that even necessary or am I dumbing it down too far?