Speakers close to the back wall will accentuate bass. Speakers in corners will accentuate the bass even further.
I recommend starting with a symmetrical layout- each speaker equidistant from the back wall, and each speaker having the same distance to the side walls of the room (if you can get away from the back wall by at least a foot and a couple of feet away from the side walls, that's not a bad start).
"Toe-in" refers to how the speakers are angled toward the listening position; in other words, not parallel to the back wall. I would start with the speakers parallel to the back wall and sit in your intended seat. Listen (eyes closed seems to help some people) to music that has a lead vocal- it should sound like the vocal is coming from between the two speakers. If the vocal seems quiet in relation to the music, angle the speakers a little bit inward toward your listening position, and listen some more. A tape measure is handy to allow you to make consistent calibrated adjustments. That's just a starting point- it can be frustrating, but try not to let it bother you, sometimes I have to go too far in a directional adjustment to know what's really happening. If you REALLY listen, you can likely get great sound without too much trouble.
A equilateral triangle is a good way to visualize the relation of the distance between the listener and the distance the speakers should be from each other. If the speakers are 8 feet apart, try sitting 8 feet back from the front baffle as a starting point- you may want to move a little back or forward from there, but establishing a baseline helps narrow the number of options.