SSRS is almost a completely different field of study from being a DBA, so, while I like SSRS, support it's use and all that, I don't know that I'd concentrate my efforts there for trying to learn the DBA job.

I like two of your choices, T-SQL and PowerShell. With that in mind, I can recommend two books:

Inside SQL Server T-SQL Querying by Itzik Ben Gan

PowerShell in a Month of Lunches by Don Jones

Those books will teach you very solid fundamentals and the authors are extremely respected professionals in their fields.

But that's just brushing the edge of SQL Server. You still need to drill down into all the other aspects, backups, restores, structure, storage, etc. To get started on that, I'll recommend my basics book, Beginning SQL Server 2008 (or 2012) Administration. It gives a pretty good overview of all aspects of the DBA job to get you going.

In addition to books, I strongly suggest hanging out on the forums here. Attempt to answer questions. This forces you to learn quite a lot. If you're not getting enough challenge at work, volunteer to build a database for a community organization or non-profit in the area.