If you want to be a DBA and you want really good, worth their weight in gold books that apply to being a DBA. Goto Amazon.com and search for Kalen Delaney. Any of her Inside SQL Server 2005 books is well worth the cost to purchase them. I own all of them, and they are a constant source of information. Another book that is really good is Ken Henderson's SQL Server 2005 Practical Troubleshooting.

I became a DBA by working through the development ranks for a few years. If you position yourself where you can learn performance tuning and the likes, you get to play with the internals side of things, which leads towards DBA type tasks.