It is written, "You shall cover (v'Sachosa) the Aron with the Paroches."
(a) I always pictured the parochet in front of rather than over the aron. How do you see it?
(b) Also, are the luchot in the aron standing up or lying down?
(a) You are correct that the Paroches was positioned in front of the Aron. However, there was a slight fold at the top of the Paroches where it bent inwards towards the area over the Aron and "covered" the Aron.
Rebbi Yoshiyah in the Gemara learns that the word "v'Sachosa" proves that the partitions (walls of a Sukah) must also be taken into account -- just like the Sechach -- when measuring the amount of shade created by the Sukah, since the verse refers to the role of the Paroches with the word "v'Sachosa." For the literal meaning of the verse, a more accurate translation than "cover" would be "You shall shield the Aron with the Paroches," or "You shall screen the Aron with the Paroches" (as in "Masach ha'Pesach), phrases which do not carry the inference that it must be on top of the Aron.
(b) The Gemara (Bava Basra 14a, Shekalim 25a) implies that everyone agrees that the Luchos were lying down flat and not standing.
Y. Shaw