I'm a convert to the elliptical, so let me join the others in praising it. A couple of things to know going into it: the motion of it can feel very unnatural at first, but don't give up! Soon you'll be able to 'ellipticate' in your sleep.
Also, it's not uncommon for your feet to slide forward on the footplates as you go. This may cause some numbness in your toes. If this happens, take a QUICK break and stamp your feet a bit.
Good luck! You can do this!