Hi
Before you dive into SQL Server, make sure you bone up on relational database design and the normal forms.
Once you understand that, I would recommend then getting to know SQL Server internals (i.e. how indexes
are stored internally, how clustered indexes differ structurally from non-clustered indexes, etc)
Before you dive into building and administering databases, first take the time to really
understand the "under the cover" fundamentals.
Chad Boyd has a series of blogs here in MSSQLTips that are excellent.
