I started by reading this book: https://www.amazon.com/gp/aw/d/047064320X/ref=mp_s_a_1_1?ie=UTF8&qid=1500714581&sr=8-1&pi=AC_SX236_SY340_FMwebp_QL65&keywords=Test+driven+development+with+c%23&dpPl=1&dpID=51XYxuW-W1L&ref=plSrch

Which (for me) was a great way to learn about it. After reading it, I watched some pluralsight courses about it (but there should be some cheap ones on udemy as well if you don't have access to pluralsight).

After that, I just started implementing the things I learned while I work. I wouldn't worry too much about the test driven design aspect at first (writing the tests before you write the code) since that's quite tricky to get the hang of and should only be applied if you know what the code will look like to a great extent.

Having said that, that's what worked for me and it might not work for you. I do recommend the book though, since it was a great and easy read.

Systems Analysis and Design in a Changing World (Sixth Edition) <-- this was the version required for a class

Seventh Edition(?)

This book is free from any programming languages and is instead supposed to aide the development of thinking and planning applications.

murach's SQL Server 2012 for developers <-- required for class

murach's SQL Server 2016

Uses SQL to further enforce "forms" for application data structures.

Professional Test Driven Development with C#: Developing Real World Applications with TDD

Book I purchased during my 4000 project class. Team based project where we had to

1. To plan out the application using skills from System Analysis and Design.
   
   
2. Create a presentation to show to a client.
   
   
3. Create a manual to help onboard developers.
   
   
4. Create a manual for clients.
   
   
5. design and deploy a database (database schematic included in onboarding manual).
   
6. Write tests for the application.
   
   
7. Deploy the application to Azure.
   
   After my research at the time, this book seemed to be the most appropriate for my scenario.