Compound bows have many different moving parts and limbs, cams and strings each play a part in making a getting the most out of it. However, as these parts are tested over and over by the manufacturers, as a beginner, you can look at these things instead which will be much more important to you as you start;
Draw length: The draw length is the distance between the bow and the pulling arm. This is an important measure as
compound bows will only draw back to a certain distance although it is adjustable within a certain limit. A lot of people fail to get the draw length right. To measure your draw length, you should measure your arm span from tip to tip, with your arms held out and divide this number by 2.5. This is the draw length you need your bow to be, and in a lot of cases it usually matches your height.
Draw Weight: It is just as important to get the correct draw weight. This is a measure of how much force you will need to apply to each shot to reach the optimum shooting stance. If you have the weight too high, you will need to put in much more effort than you should be and will quickly become tired and your shots will not be accurate.
As a general rule of thumb, for recreational archery and target practice you should aim for 75% of your strength level. As a general rule of thumb you can approximate your draw weight by taking your weight in pounds and divide it by 2.5. Please bear in mind that as people are different this may be slightly off. If you are unsure, check with your local archery store.
IBO speed:The IBO speed is a measurement of the bows speed, in feet per second (fps). The IBO speed is taken as a measure with a 350gram arrow, 30″ long at a 70lb draw weight. You may find you have trouble reaching the IBO speed if your setup is different to this the measure is constant across different bows so it is a good indicator.