I live too far away to directly help.
But,
for info on aesthetics of aquascaping try
www.manhattanreefs.com/.../reefs.../100520-aesthetics-aquascaping.html
In terms of physical construction there are many approaches.
You can simply stack them. If so place them directly on the glass bottom so any burrowing creatures don't cause them to shift.
At our January meeting, Chris demonstrated how to use a masonry drill bit to create holes to insert plastic rods. He uses plastic tube coat hangars as his source for rods. This allows for easy disassembly if you want to alter your reef sometime in the future.
For cementing the rocks together there is a product called pond foam that is very effective. It has a black bumpy appearance so it blends in unless your using bleached dry rock. For white rock you can try J Weld's epoxy that is labeled for under water use and available in most hardware stores. I don't find it a strong adhesive but if you use a large enough piece for it to work into cavities, when it hardens it will lock the rocks together. It mixes to white so it wouldn't be an eyesore when your waiting for white dryrock to "purple up".