Guru means teacher, at least on a simple level. More often, the word guru is synonymous with a master who is followed by devotees. It is a term that is often associated with eastern religions and spiritual practices, but it can also describe a wider range of teacher-student relationships, where there is an intense bond or loyalty. Guru-devotee relationships can be wonderful and a true source of transformation. However the guru/teacher has a tremendous responsibility and power that needs careful attention. In any transformative relationship there is much to be learned and mastered by the student, but ultimately the goal should be to gain independence from the teacher.
The absolute best teachers/gurus to follow are the ones that do not want or need followers. They encourage you to find your own source of power, your own well of creativity, your own revelations. Guidance is great, but learning through living is better.
The problem with seeking a guru is the process of turning over all your independent thought to another in the hopes that their wisdom will fix all your problems. It is seeking external approval when the true need is internal.
It is very important to choose a teacher wisely. Learn, study, but do more. Study them. Listen to the internal Guru. What does your inner wise one say? A great teacher will echo the words in your heart. There is an upliftment, a great freedom, an inner peace from wise words.