how would you go about testing collision detection ? i know the um is x is in x2 thing.. but umm how would you check for stuff like stairs? how do you check if you are at stairs and then go up the stairs? would you just do ifs to all objects? or is there better ways?

Usually you do not need to do precise collision detection. A technique that is frequently used is to find a simple shape, such as a box or a sphere, that tightly encloses each game object. For more complex objects, like people, you might use multiple bounding shapes. For example, put a sphere around the head and a box around each of the torso, arms, hands, etc.

Then collision detection is greatly simplified. All you need to do is determine whether any of the bounds have collided.

If you don't know how to do that then check out http://www.magic-software.com in the computer graphics section.