[So these speakers should go...?]

So I currently have a room that is about 15x15. I have a noob setup with the HD 300 Klipsch. I just recently upgraded 2 speakers to the RB-51's. Right now I have them placed in the back left and right. Which is closer to me. Would it be useless to put it in the back right and left? Or should i put them in the front right and left?

[Best placement for the RB-51's?]

I heard since they have a rear port in the back, hanging them againest a wall would take away from the clarity and sound. So what would you guys reccomend me doing as far as placement and mounting these speakers.

[So will my YAMAHA RX-V367 AV Receiver support RB-51 II Bookshelf Speaker? (NOOB)]

Thanks for your input and warm welcome. I am glad to see that it will work and my only concern now is when will i know that my entry level yamaha reciever isn't cutting it anymore? And, when i do choose to upgrade what should i be looking in to? What specs should i look for?

[So will my YAMAHA RX-V367 AV Receiver support RB-51 II Bookshelf Speaker? (NOOB)]

I am quite new to this whole audio thing and currently I have the Klipsch 300 surround system. I want to switch out my front L & R speaker to RB-51's.

1) Will my amp support this?

2) Will the sound be weird with half RB speakers and half HD 300 series?

3) Is there another route I should be taking?

Thanks guys!