Do you need to worship the Buddha if you are Buddhist?
This is a normal, and honestly, difficult to answer question. The Buddha said that he came to this world to point out the way. He said not to look at the finger, but at the way. So, why all these images of the Buddha? Do Buddhists worship him? Is he a god for them? What the heck those Buddhists think anyway? Here in the West we have presuppositions about what is Buddhism that we acquired thanks to Hollywood. Buddhism, however, is much more complex than that image that we have.
The scriptures say that the Buddha didn't want people to worship him. Anyway, after his Parinirvana(passing), his followers cremated his body and took some relics. Many of these followers (specially the lay ones) started to worship these artifacts that had a relationship to the Buddha. They could be the relics of his cremation or simply objects that the Buddha touched during his life, like his begging ball. Eventually, they built great and beautiful shrines to hold and worship these objects.
Why do they do that? What is the meaning of this worship? Are these objects idols? Do they represent the Buddha, and therefore, they worship the Buddha? Is he a God?
Well, according to Buddhism, the Buddha isn't a god (he is a god according to Hinduism, ironic, eh?). He isn't present in this world anymore. After his Parinirvana, he passed from the cycle of death and rebirth. He doesn't exist anymore like us. He can't influence this world, at least directly. That is exactly what these worshipers believed.
They believed that the Buddha wasn't present anymore, but he left a sustaining power in these objects. What is this sustaining power? Is this superstition? Well, something like it. This sustaining power could affect their karma. That is, by worshiping these objects that have the power of the Buddha, they will have a better rebirth in a future life. Remember that Buddhist believe that, to achieve Nirvana, you need to go through a great number of lives. So, it is better for you to have a good rebirth, having a better chance to advance in your path to enlightenment in a future life, and for the fun of it also, of course.
Lay followers are the ones who generally engaged in this kind of worship. Monks and nuns also worshiped these objects, but with a different goal in mind. They worshiped these objects in a kind of meditation, to be reminded of the Buddha's teaching.
What I talked about until now could be applied to what is considered traditional Buddhism, that is, the tradition practiced by the early community of followers after the death of the Buddha. Today, the school of Buddhism that tries to imitate this traditional ideal is the Theravada. Theravada Buddhism is practiced in South East Asia: Sri Lanka, Thailand and Burma. It could be considered the conservative branch of Buddhism.
When we talk about worship in Buddhism, inevitably we have to talk about the Mahayana school. The Mahayana is a reform movement that emerged in India around the beginning of the A.D. era. It changes the style, the tone and the content of Buddhist practice in profound ways.
With the Mahayana, Buddhism becomes less individualist and more compassionate (and more worshipful). In many varieties of the Mahayana, you need to rely not in your own capabilities, but in the power of a bodhisattva (something like a god), to achieve enlightenment or salvation. If this sounds like anything but Buddhism, you don't really know Buddhism.
Buddhism is so complex that I think is impossible to answer with a yes or no to the question that is the title of this article. It is also this way with any question regarding Buddhism. Like a Zen monk would say, it is better just to see it and not to talk about it (in some aspects).