...
I have a background but am by not means a professional in the field.
In very tight some projects I do end up having to help build mock-ups and here are the resources I usehelping with the initial kickoff concepts before engaging professional creative people, or just build a mockup. This page is a reference to the the resources I use to help get us there.
Design Templates
http://www.templates.com/ - collection of free and paid templates.
...