This is a question that almost borders on mystical philosophy and you'll get answers on both sides. I crimp ALL my hand-loads (but I'm weird)--there are different types of crimps and pressures so it depends on the situation and weapon. If you're doing "conventional" non-compressed loads simply follow the directions in the reload guide--most of the time you don't need a crimp for a conventional bolt rifle. As you reload more and more different bullets and cases you'll get a feel for what needs crimping and what doesn't. Unless you're starting out with pistol loads which have to have a healthy roll crimp--I agree with keep-it-simple and start with easy loads (308 being the easiest in MO).