Pre try this:
This surround speaker recommendation is for 5.1 setup only. It is because a 7.1 or even 8.1 HT setup will have different speaker placements.
Normally, using taller stands like a 38-inch pair for your surrounds is okay if you have ample space at the sides or rears of the listening position. The surrounds are place either at both sides of the listening position or slightly at the back.
If the position of the speakers are at the sides they would face each other. However, if the speakers are a little bit behind the listener, the speakers would face forward where your video screen located. But read the user manual also. Some speaker manufacturers would recommend that the speakers at the back should directly face the head of the listener for optimum performance. My recommendation, try to experiment.
If you do not have enough space at the sides or rears of you listening position like me, the surrounds setup may require speaker mounts that you attach to the wall. Sound Dimension at Park Square 1 sells these good types of speaker mounts that can accomodate biggers speakers, unlike the ones the you buy at SM.
Please see picture:
The recommended height is 6 inches above the head. For me, I read somewhere that for this kind of setup the speakers should be facing each other. And that's what I did.
Try to experiment on the position of the speakers until you get the sound that you like.
Hope this helps.