This question gets asked a lot. You can search out the answers. In fact, I'd practice learning how to look up stuff on the internet. Don't assume that you need to memorize every T-SQL command. Instead just learn how to put them together and then rely on the fact that there is a gigantic resource available to you through the internet.

But, the one book I absolutely recommend for those getting started is Itzik Ben Gan's T-SQL Querying. It's a must-read. He also has a fundamentals book that's very good.