This could be a long post....and I have little time.
First, contact the manufacturer for their suggestions. Some speakers "like" toe-in, some don't. Also it's simply a personal taste issue. I generally like a good bit of toe-in (but didn't on my Dunleavy SC4)...and sitting just slightly within an equilateral triangle in terms of distance. Example: if speakers are 7 feet apart, sit 6-ish feet away.
I would place them equally, *at least* two feet into the room (depending on room size). As a starting point, try 1/5th the length of the room. If your speakers are firing down the long wall (as they *generally* should be)...and that room is 20 feet long, place the speakers 4 feet into the room. There's no substitute for experimentation.
*Unequal* distances from side walls will help too.
In your case...placing the subwoofer will be key imo...and require a good bit of experimenting. Can't get into that right now, but maybe google subwoofer placement. Check out the REL (!!!) or Hsu Research websites for tips. For music listening, to get a sub to "disappear" ain't easy. For starters, stay away from corners! Stereophile.com forums could be a great resource for you.