bird,sterling,ross,union,wms or any of the cheap cylinders are easier to start with, if there is a poundland near you they sell ross cylinders(just a pound) my 10 year old daughter can open all the above they are not hard but will give you more feedback
this may be off topic but i was wondering if you could give me examples of high security locks, and how many pins would be in the lock,
and finally what type of picks should i use