I cannot tell you from first-hand experience if piercings will help to enhance your sex life, because I personally don't have any body piercings. (While I have considered getting some, I have never gotten around to it, and it's likely that I never will.) However, I have many friends who have various parts of their body pierced -- and most of them have great things to say about their piercings.
The most common part pierced for sexual pleasures is the tongue. I am told it does not really hurt to have the tongue pierced, and the benefits are somewhat obvious. When used for oral sex, the small metal ball or tongue ring that is on the tip of the ring will add pressure, tease, and bring a new sensation to the experience for your lover. People that use them seem to get off on the fact that their partner enjoys oral sex so much.
Meanwhile, the one on the receiving end usually also loves the power of the tongue ring. For some extra fun, you can drink something warm or suck on some ice prior to performing oral. This will change the temperature of both your mouth and the tongue ring for added effect.
When it comes to other parts, I can tell you that a piercing will make that particular part of your body part more sensitive. For example, people who have their nipples pierced find it highly arousing to have their nipples toyed with during sex (or anytime, really). The same can be said for men brave enough to have a penis piercing and women that go with labia or clitoral hood piercings.
An interesting side story that just might answer your question comes courtesy of a friend of mine who once worked in a piercing parlor. When you are pierced, someone washes or cleans your body part prior to the piercing -- and that was my friend's job. One day he needed to clean up a girl who was getting a vaginal piercing (I don't recall what specific area). The girl already had several piercings in that area and had decided to add one more.
My friend became increasingly frustrated with his job because he was having a tough time cleaning the area. However, the girl was so sensitive from the number of piercings she already had, that the motion of cleaning her brought her to orgasm repeatedly.
So, yes, it's safe to say that piercings can help enhance your sexual pleasure in one specific manner. Just make sure if you are going to get a new hole in your body, you go with a person licensed in piercing. Request to see the piercing tools they use ahead of time, and ask how the overall process will occur.
Also, make sure that you are going to commit to keeping your piercing clean and well taken care of, in order to avoid any problems or possible infections. Things of that nature would, of course, seriously reduce pleasure.
4 Ways to sweep him off his feet
6 Steps to a sexy massage
5 Things he wants you to say in bed