I agree 100% with Keith! Buy an assembled stepper-motor driver board ans save yourself a lot of frustration.
After you've learned a bit more, you can start building things from scratch. (But even then, it's not always worthwhile.) Or when you need something that you can't buy pre-made, That's a good time to design & build something yourself.
I have a L6219 (http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00000092.pdf)
and a breadboard. I have been reading vague tutorials all night but can't get my head around it. Does anyone know any basic tutorials for getting started that I could look into? Or does anyone have any useful circuit diagrams or anything?
Page 12 of the data sheet shows a schematic for a "typical application circuit". But you'll have a lot more fun, a lot sooner, if you just buy an assembled board.