Applying for a DBA position can involve a lot of different knowledge areas. You need to understand what the job is that you are applying for and determine if your skills match the position. There are jobs that are more involved in the database administration portion of the work and there are other jobs that need more database developer, SSIS, or SSRS background. While these could all be advertised under the label of Database Administrator you would need to look at the details of the position being posted to better understand what the company is looking for. There are different sites for different points about certain topics. You can start by looking up best practices for setting up databases, indexing, and so forth. As you find articles that peak your interest in certain area's you can branch off into those areas and learn more. One of the things a good DBA has is the ability to observe events to capture what is going on, that helps them solve the issue or to research the issue to find the solution. The one thing about technology is that if you want to keep your job and be an asset to your company you never stop learning so forget about just looking up the data just for the interview, it will be a continual process if you want to be successful. I have attached a document that pretty much sums up characteristics any good employee should have but is written for DBAs. I do not endorse the products listed, I just think it's a good summary.