If you want to learn SQL, I can suggest you to download and install MS SQL Server Developer Edition for free.
Then you can download sample database AdventureWorks for SQL Server and starting to try and see how SQL commands and statements behave on this sample data
Please check the following links for SQL Server 2008 download links
and for AdventureWorks sample database download link
After you have a test environment, you can ask your questions on forums like Kodyaz or MSDN, ASP.NET etc.