What speakers are they? You should have a diagram from the manufacturer that has the 'recommended listening' level to the speaker. Place them a little above ear level and you'll be fine. I'm guessing you have cubes so mounting them in the corners is fine too. You need speaker wire...how many feet do you need and what speakers do you have?
www.partsexpress.com has 100' 12 guage for $35, can't beat that and I think they have flat wire there too.
Nobody will notice the wires if the installation is done right.
