Where oh where do I place my speakers

I just bought a Yamaha RX-Z1. This unit allows for front main (L/R), front and rear centers, Rear (L/R), and front effect speakers (F/R) I have a pair of NHT VT-2 for the front main speakers, I have four (4) NHT VS-2, and a pair of HDP-2 speakers. I was initially planning to use the HDP-2 as the rear speakers and the VS-2 speakers as the front and rear center and front effect speakers. I've heard that the HDP-2 make great side effect speakers.

1) Should I use the VS-2 speakers for the front and rear centers and the rear left and right speakers and use the HDP-2 speakers as side effect speakers?

2) Does it matter if I use side effect speakers instead of front effect speakers?

3) Where should I place the front or side effect speakers?

Easy. No sarcasim intended--The fronts go in the front near the tv,but not to close(4ft each side;away from the tv) The rears ,if you can, go behind you.(lined up with the fronts)i.e. if the fronts are 3ft from the side wall the rears will be 3 ft. from that same wall. The sides will be about 1/2 way between front and rear. The rear center behind you between the rear speakers.
Thanks for the info. I understand where to place most of the speakers. The fronts, rears, and centers are pretty easy to figure out. It's the effect speakers. My receiver manual says to use front effect speakers, but I have Hybrid Dipole (NHT HDP-2) speakers which need to be mounted on the side. Mounting them equal distance between the fronts and rears would put one side of the effects past the seating area. Would it be better to mount them between the two rows of seating. This puts them much closer to the rear speakers.

You can't use the 'front effects' channels of the RX-Z1 for 'side effects'. It will mess everything up.

The 'front effects' are using info from the front mains.Basically it is ambient info. Thats how it was explained to me. Which seems logical.