Umm.. I had this kind of problem too.. Maybe my way isn't the best.. still works.. All I do is save the x,y coords, file, parameters into a textfile like this:

0,0(wall.bmp,0,0,1)
0,1(door.bmp,1,0,0)

The parameters can include whether the object is a wall (you can't walk through), or maybe it takes you to another map once you walk on it..)

Tell me what you think