Hi Oshyan,
I have read the documentation and looked at the tutorials but it's possible I may have missed something. I have a scene with a camera which follows a meandering river with mountains on either side. My camera path has keyframes at 3 camera positions - frames 1, 400, and 800. With this configuration, my camera starts moving too fast from the start rather than starting from a stationary position and gaining speed gradually. My first attempt to slow down the starting speed was to add key frames at several positions between 1 and 100 and adjust the position xyz curves in the animation panel so that they are more horizontal. In other words, I'm trying to make the tangent to the curves at the first frame more horizontal for all 3 coordinates. When I try to adjust the corresponding camera rotation coordinates at the keyframed positions, I get bogged down trying to reproduce the camera aim that I had before I inserted the new key frames. In the end I gave up and decided to ask for help.