[ingrownpsyche]

An adder in functional Verilog:

a + b

Best go with structural if you want to actually learn something. This book ( http://www.amazon.com/The-Elements-Computing-Systems-Princip... ) is very good and I think still stands as the best introduction to this type of stuff I've seen. It's also presented in a straight forward enough way that it's good enough self-study for anyone with some programming experience.

[p1esk]

Here's a link to the course based on that book: http://www.nand2tetris.org/course.php

Note, however, that it does not use actual hardware, nor a real hardware description language - it's just a hardware simulator (this might be important for someone who's interested in FPGA per se).