Yes it is normal for the dies to leave an impression in the plates and for the to sound like they are cracking
Unless you are using the skinny sizzlets type dies you really don't need the booklet...you just put down one plate, then the die, then the fabric/felt and then the other plate.
If you want to cut just one circle you just have to cut the fabric/felt to the size enough to cover just that circle.
I'm a sizzix wholesaler so if you need any more supplies or anything I wholesale them for 40-50% off and I also do buy here on HG for sizzix. You can also email me with any questions and if I don't know the answer I can call my rep and find out for you!