To get into the room of blue, skate towards the big half pipe. When you are about half way up the pipe, skate left into the wall. This will put you into the blue room, if you do it right it will take you to the very top of the level where you can pull off some insane tricks.
Extra points
Pause and hold L1 + L2 + R1 + R2 then press Circle repetitively. Each time you press Circle your points will increase by 5,000. NOTE: this only works during a run.
Swimming pool fun
On the court house level there should be a ramp with a fence in front of it. You can ollie off the ramp and over the fence. The swimming pool is over there. To get out just go on the other side and ollie off the ramp to get back to the level.