Perhaps the most obvious misconception (obvious looking back and thinking about it) is listed by Paul as the below;
24x) you can restore a backup to any uplevel version of SQL Server
No. You can only restore a database from two versions back (i.e. you cannot directly restore
a SQL Server 7.0 database to SQL Server 2008).
This isn't something that I knew, I mean sure I've restored / upgraded plenty of databases in my time but never really given the number of uplevel versions a second thought. I imagine this is more a matter of luck rather than judgement on my part.
I don't have any SQL Server 7 databases to support any more but still have the odd SQL Server 2000 database. Going off this I shouldn't be able to restore a SQL Server 2000 database to a SQL Server 2008 R2 server right? I will give this a try and let you all know.