I would just like to second some of the opinions here.
Masturbation is perfectly normal and under most circumstances not worth suppressing. Either its gotten out of hand (which would have to be hours a day, pretty extreme) or you have mistaken notions about the value of your own sexuality. Its going to be there whether you masturbate or not, that energy will come out in some form or another. I recommend that you approach your own sexuality from an entirely different perspective, as a natural and exciting thing. It seems to me that the only real waste of time is time spent suppressing your sexuality, not time spent expressing it.
Pornography is a different story. While I think erotic materials are perfectly acceptable, there are several factors that make the modern form of pornography different and harmful. The accessibility of pornography makes it really easy for people to get addicted to it. This is bad for several reasons. The most important reason for me is that it totally skews your view of other people, mostly women, as sex objects. Someone that regularly watches pornography will find it really difficult to switch to a monogamous relationship. Pornography makes it difficult to enjoy actual sex because they have become used to sex as a one sided deal, not an interaction between people. Theres also the exploitative nature of the pornography industry that many people find is a turn off from porn itself.
These are just my impressions, there are probably numerous exceptions to all of these things. But, in my experience, you will be the best judge as to whether your thoughts and actions are in your best interests.