Yeah, the stairs are a bit confusing at first. You have to have a downward staircase one level higher than an upward staircase on the same tile. The staircases must be facing in opposite directions, or they won't work. Also, make sure that each staircase is surrounded by walls on all sides except the side where you will enter/leave, or it won't look right. Good luck, hopefully I haven't confused you more!

Oh thanks a billion. This has been making me so angry for the past few days until I decided to post on here. Really, thanks again for your help.

You're welcome. The stair thing frustrated me too at first. After you figure it out, it become a little easier, but I still always test stairways after I add them to make sure I didn't mess up the placement.