Question: For example in Peggle or Apple Jack, the user can move around a curve showing where the ball (or the washing machine / panda or whatever) is about to go before the user has requested that the projectile is launched. I know i need to use an equation to plot the points but I'm no mathematician (anymore :(). Can anybody be so kind as to provide me with the correct equation and tell me what I should substitute in to get my X any Y values given a certain time and initial velocity.

Answer: 
If this is a projectile following a simple ballistic trajectory, you can use the closed-form expressions provided here:

<http://en.wikipedia.org/wiki/Trajectory_of_a_projectile>

If not, it might be a lot simpler to simulate the effect of all the forces on the body for each (small) time-step, updating its position and velocity accordingly. This technique is more robust; you can add a lot more complexity to the problem without changing the basic methodology.
You could use newton's method of approx. solving. The problem here is that you need to integrate - so you have to define the trade-off between preciseness and calculation time. 

**RK4** is the method that is best in my opinion - it is fast and still very precise.

You can read more info at <http://gafferongames.com/game-physics/integration-basics/>