You may visit the British Council page for IELTS for sample exercises.
A simple Google search will give you a lot of material on speaking exercises for IELTS.
However, who you practice with is an important question. Working with a friend or a fellow IELTS taker is good but sometimes, when the other guy too is a learner, he would not be able to provide you with the right insights into your shortcomings and means to remove them.
This is why finding a teacher with prior IELTS successes is critical. If you are planning to join a classroom course, then ask about what kind of practice they would give you. More than the material, quality of practice would be much more important.