I had someone send me a note recently asking some questions about how to get set up to work with SQL Server. This was a person that had used SQL Server in the past, but had become a manager and then lost their job. So they wanted to start working with SQL Server and get a new job, however they didn’t have a server or many resources.
My first recommendation is that you grab the SQL Server developer edition for US$50. You can get it from Microsoft, Amazon, or many other places, but this is essential. It gives you a good basic point from which to start and test features.
However if you don’t have a spare machine, or you don’t want to put SQL Server on what you have for some reason, you have another option.
TechNet Virtual Labs
There are a whole variety of labs available, including a series on SQL Server 2008 and other versions. These allow you to RDP to a virtual instance of SQL Server and actually practice working on things.
There are other labs for Windows, Exchange, etc. You can spend time working on these technologies, either guided or unguided, and get some hands on practice. You can’t necessarily save your work, but this is a great way for you to get started on some technology that you want to add to your skillset and resume.