Old School Programmer - ARGH ( COBOL ) - Yes I still pump blood, lol.
New to arduino & electronics and don't want to burn anything up...
I want to write a program, but I don't want to create any bugs...
Hardware errors aren't as common as software errors, which is an indication of how difficult programming is... But sooner or later, you are going to hook-up something wrong, or backwards, and something bad is going to happen. I'm an old-time hardware guy and it still happens to me once in awhile.
Be careful, and hopefully you won't burn-out your Arduino or your relay board. When it comes to LEDs, resistors, capacitors, and cheap IC's or other cheap parts... Buy extras! 