Help with Arduino Mega 2560 Timer Interrupts

I'm trying to learn how to work with interrupts, but the syntax to do so is very archaic. I'm using the Arduino Mega 2560 as my platform of development. I would like to know how can I setup an interrupt that will flick an LED on and off every 1000 milliseconds. I feel solid about interrupts in theory, but not in practice. Can somebody post an example of a program that would blink an LED using timer interrupts and maybe brief explanations of what is going on?

Note: I know it would also be possible to blink an LED within the loop() function, but I need to do other things using interrupts, and the loop function would not be suitable for those things (video generation on VGA).

Thanks in advance!