Not For Profit Business Plan Template
But don't confuse simple wording and formats with simple thinking. The reason you're keeping it simple isn't because you haven't developed your idea fully. You're keeping it simple so you can get your point across quickly and easily to whoever's reading it.
Of course, there are exceptions to the rule. I recently saw a plan for a chain of coffee shops, for example, that included photos of the proposed location, mock-ups of menus and maps of other proposed locations. The graphics made the plan longer, but they added real value. Product shots, location shots, menus, blueprints, floor plans, logos and signage photos are useful.