Newt Paludarium

[Mako Man111]

With my spare 20 gallon high tank I would like to create a paludarium of some sort to house a newt. I just don't really know where to get started.

What material should I use to mold a background and what can I use to paint it?

Also, can I just use silicon to hold rocks together and to hold them to the back ground?

Also, does anybody know of any good plants that go on land?

Thanks