What’s been said about it being easy but hard is very true.
I have seen some terrible coding done in T-SQL by people who should know better. If your company has a DBA a chat with them about what it is you are doing is well advised.
Infrastructure teams especially those that don’t ‘get’ SQL Server get miffed when they have to put a database onto a server with 16 CPU’s and 32Gb of Ram when because the coders did a poor job on the design and don’t know to ensure good table relationships, create useful indexes or think about column statistics.
W3Schools is good to get started, then one of the dummies books and then ‘T-SQL Querying’ by Itzik Ben-Gan for the language and Christan Bolton’s book for how the SQL Server DB engine works and can be tuned.
Once you have that lot mastered give me a call, I’ll probably have a job for you 🙂