Mark "Spookshow" Peterson has assembled what is probably the most comprehensive on-line source of information for N scale equipment. His locomotive reviews are quite useful and generally mirror my experiences in working with many of these models over the years. Mr. Peterson is very straight forward in his approach and he doesn't mince words. Plus, he mixes in a good bit of humor which keeps things entertaining.
A variety of topics including motive power, rolling stock, scenery and maintenance are included. From the title page (link provided below), just use the filter to search the categories you want. Mr. Peterson has put forth much effort into researching and presenting this material and I recommend his site highly.
http://www.spookshow.net/trainstuff.html
Bob