Pop shields are an essential piece of kit in the world of voiceovers. You can buy a pop shield from about £20, but if you are worried about money, you can make you own using a wire coat hanger and a pair of tights.
Without a pop shield, plosives (hard consonant sounds at the beginning of words, e.g. P's in Peter Piper picked a peck of pickled peppers) are exaggerated and are likely to ruin the recording. The pop shield softens the harshness of the sound.
A professional pop shield will come with a clamp to attach to the mic stand or booth. It is important that you do not connect it directly to the microphone, as any vibrations will be transferred to the mic and that will ruin your voiceover.