Here's a simple crystal oscillator project you can build
this was the first thinig i thought of when i read the op. i built one myself. very easy, very useful. it has definitely earned a place in my tool box. i dont have the fancy cutter, but hoging out a few squares with a dremmel tool works just as well.
now while we are on the subject of learning.....
in addition to different wave forms, as you posted, i have noticed widely different swings in amplitude between different xtals as well. with w2aew's circuit, some would put out barely 1v p/p signals, while others would be up to the 9v supply voltage.