Here are some Rudolf Steiner quotes that seem to me particularly relevant when giving you a first good impression of what he was all about. Enjoy!
“Living through deeds of love and letting others live with understanding for their own will, is the fundamental maxim of the free human being.” – Rudolf Steiner (The Philosophy of Spiritual Activity, 1894)
“Each individual is a species unto himself.” – Rudolf Steiner (Theosophy, 1904)
“Healing is only possible when in the mirror of the human soul, the whole community is formed, and in the community the individual soul's strength lives.” – Rudolf Steiner (Truth-Wrought Words, GA 40)

“The most important thing in life is to develop the ability to think clearly and independently.” – Rudolf Steiner (Learning to See in the Spiritual World, GA 350)
“One can experience much in the spiritual world, one can be able to tell much about it; the things one relates can be genuine images, the image can be truly perceived correctly—therefore, it need not be true. And however paradoxical it may sound, it must be said that it is now indispensable, something extremely important, that those who wish to enter the spiritual world bring the faculty of judgment from the ordinary world. Whoever has learned to develop sound human understanding in the ordinary world, who does not deceive themselves and does not allow themselves to be deceived in the ordinary world, will also bring sound human understanding into the spiritual world and correctly assess the things they see there.” – Rudolf Steiner (Wahrheiten und Irrtümer der Geistesforschung, GA 69a)
“Anthroposophy is a way of knowledge that wants to lead the spiritual inside the human being to the spiritual in the cosmos.” – Rudolf Steiner, Anthroposophical Leading Thoughts (GA 26)
“To truly know the world, look deeply within your own being. To truly know yourself, look deeply into the world.” – Rudolf Steiner (Steiner Verses and Meditations, 2004)
“There is little value in knowing plants, animals and minerals unless one can find the stars working in every one of them.” – Rudolf Steiner (Vorträge und Kurse über christlich-religiöses Wirken, Band 5, GA 346)
“Love is for the world what the sun is for outer life; no soul can grow when love in the world is eliminated. Love is the moral sun of the world.” – Rudolf Steiner (Love and Its Meaning In The World, GA 143)
“Love is higher than opinion. If people love one another the most varied opinions can be reconciled – thus one of the most important tasks for humankind today and in the future is that we should learn to live together and understand one another. If this human fellowship is not achieved, all talk of development is empty.” – Rudolf Steiner (At the Gates of Spiritual Science, GA 195)
"Imagine two glasses, one empty, the other half-filled. Then imagine pouring water from the half-filled glass into the empty one, and the half-filled glass becoming increasingly full. The materialist finds this absurd. But a thought suitable for meditation is not about something physically real, but about something that forms representations in the soul. Precisely because such an idea does not refer to anything real, it distracts us from sensory reality. However, it can be a symbol, namely for the soul process connected to the mystery of love. With love, it happens as with the half-filled glass from which one pours into an empty one, and the half-filled glass nevertheless becomes fuller. The soul does not become emptier; it becomes fuller in proportion to its giving. This symbol can have such a meaning." - Rudolf Steiner (Die Welt des Geistes und ihr Hereinragen in das physische Dasein, GA 150)
“A spiritual science without love would pose a danger to humanity. However, we should not preach love; love must come into the world—and so it will—by spreading knowledge of truly spiritual things. Spiritual science and actions that arise from true love must form one inseparable whole.” – Rudolf Steiner (Love and its Meaning in the World, GA 143)
“Love starts when we push aside our ego and make room for someone else.” - Rudolf Steiner (How to Know Higher Worlds, 1904)
„In the future, man will stand in a much more intimate relationship with world law than at present. And the spiritual disciple anticipates this intimacy in the development. The head with the brain is only a transitional organ of knowledge. The organ that will actually take a deep and at the same time powerful look into the world has its basis in the present heart. But it should be noted that this organ is born in the present heart. In order to become an organ of cognition, the heart must still be transformed in the most manifold ways. But this heart is the source and fountainhead of the human stage of the future." - Rudolf Steiner (Aus den Inhalten der esoterischen Stunden, Band I, GA 266/1)
“The path to the heart goes through the head. Love is no exception. When love is not merely an expression of the sexual drive, it is based on the images we form of the beloved being. And the more idealistic these images are, the more inspiration love imparts. Here, too, thought is the father of feeling. It is said that love blinds one to the shortcomings of the beloved being. One could also reverse the situation and say: Love opens one's eyes to its own excellences. Many unsuspectingly pass by these excellences without noticing them. That one person sees them, and precisely because of that, love awakens in their soul.” – Rudolf Steiner (The Philosophy of Spiritual Activity, 1894)
"Nowadays, before becoming clairvoyant, one must absolutely be a rational thinker. One must be capable of logical and clear thought. Anyone who would seek the gift of clairvoyance without first developing the gift of rational, clear thought would receive a poor gift. Instead of being guided to a higher, spiritual world, they would find themselves in a world of fantasies, where all control is absent, in a world that presents itself to them as the dream world presents itself chaotically to the dreaming person.”- Rudolf Steiner (Ursprung und Ziel des Menschen: Grundbegriffe der Geisteswissenschaft, GA 53)
“There is a fundamental principle which must not be transgressed if any goal at all is to be reached: every branch of knowledge which you seek only to enrich your own learning, only to accumulate treasure for yourself, leads you away from the path. But all knowledge which you seek for working in the service of humanity, and for the uplifting of the world, brings you a step forward. This law must be rightly observed. Nor is one a genuine disciple until he has adopted it as a guide for his whole life.” – Rudolf Steiner (How to Know Higher Worlds, GA 10)
“The more a person manages to make his concepts flexible, the more he will understand his fellow human beings.” – Rudolf Steiner
“You have no idea how unimportant is all that the teacher says or does not say on the surface, and how important what he himself is as teacher.” – Rudolf Steiner (Heilpädagogischer Kurs, GA 317)
“If you try to make one step forward in your knowledge of hidden truths, then simultaneously do three steps in the development of your character to good.” – Rudolf Steiner (How to Know Higher Worlds, 1904)
“It will always appear to be true that those who truly possess knowledge, are the most humble of human beings.” – Rudolf Steiner (How to Know Higher Worlds, 1904
“If we do not develop within ourselves this deeply rooted feeling that there is something higher than ourselves, we shall never find the strength to evolve into something higher.” – Rudolf Steiner (How to Know Higher Worlds, 1904)
“The wisest can learn most from a child. And when someone who is himself able to look into the spiritual worlds has a child before him, with the stream that rises up into the spiritual world, it is as if — forgive the homely expression — he has in the child something like a telephone-line into the spiritual worlds. The spiritual world speaks through the child, but men are not aware of it. The wisest can learn most from a child. It is not the child that is speaking, but the angel is speaking out of the child. ” – Rudolf Steiner (Die Mission der neuen Geistesoffenbarung, GA 127)
“If you cannot understand something, then it is best not to judge, instead of condemning.” – Rudolf Steiner (How to Know Higher Worlds, 1904)
“Music is the expression of the will of nature while all other arts are expressions of the idea of nature.” – Rudolf Steiner (Das Wesen des Musikalischen und das Tonerlebnis im Menschen, GA 183)
For more Rudolf Steiner quotes in English, I heartily recommend The Great Rudolf Steiner Quotes Site. Run by Dutchman Ridzerd van Dijk, this site offers over 1,600 great and insightful quotes from the master. Enjoy!