Speaker Mounting and Placement

I just purchased Castle Richmond speakers, which I must use as truly 'bookshelf' speakers because I don't have room for stands. Any comments on placement from rear and side walls? Should one use spikes on the shelf to separate minimize the contact with the shelves or use a 'inertia base' of sand or lead shot separated from the shelves with an air or other cushion?
I would recommend spikes. You want ridged coupling for speakers. If there are books (heavy ones) on the shelf this can also help. The shelf material is likely to be the biggest problem. If you can replace the shelves that the speakers are on with something that is non-resonant (nothing is really non-resonant, but wood is probably about the worst material). Veneered MDF would be preferable to solid wood. I have a set of bookshelf Epos speakers in a family room on Granite on tiptoes. Spikes in the speaker would be even better, but I haven't gone to that length yet. The granite works very well--you could probably get a couple of remnant pieces cut from your local kitchen counter top store to sit on top of your shelves and then use the tip toes or spikes.
Very nice little speakers in my opinion. I've never tried bookshelf mounting, so i can't offer any advice. I figured that you wouldn't mind a "pat on the back" and a "congratulations on your choice" though : ) Sean