I recently purchased some Microsoft Exam prep books for SQL 2012, and I find them to be better written than the ones for SQL 2008. But you still need practical experience that comes from resolving issues that affect real database users, so I'll repeat what others have said and volunteer, get an internship or an entry-level IT job that allows you at least some exposure to SQL Server support.

Also, with the increased emphasis on High Availability, you should have either a high-end computer capable of running several virtual machines simultaniously, or pick up several second hand computers on which to install separate SQL instances for practicing mirroring, failover clusters, always-on, etc.