Classic games?
jim-greer: I got started on my Apple ][+ mostly by typing in games from magazines and then modifying them. Softalk was the best - http://en.wikipedia.org/wiki/Softalk. They had a Rogue style overhead view ASCII art dungeon crawler - I added my own weapons and monsters and stuff.Typing something in was a great way to learn how it worked. 
The Shootorials section of Kongregate is our attempt to recreate that for Flash games - http://www.kongregate.com/labs