Thought I'd list this here rather than the layout planning as the plans are primarily O and S scale rather than N. (Mods please move if need be.) However some of these have nice simple but effect plans that may be of use to N scalers. As said because these are for the larger scales reducing the layouts is a possibility.
Free access to the Classic Toy Train database.
http://ctt.trains.com/trackplans-search.aspx?size=%7b356B04DF-7D1D-4F12-905B-95771066FC38%7d&scale=&brand=&curve=&keywords= (http://ctt.trains.com/trackplans-search.aspx?size=%7b356B04DF-7D1D-4F12-905B-95771066FC38%7d&scale=&brand=&curve=&keywords=)