I always recommend a site called
www.messier45.com
You can search for all types of objects and it will give information including an image. (and maps).
eg. BN m<11 in orion
will list all bright nebulae in Orion with magnitude<11
BN m<10 size>2' dec<30
will list all bright nebula larger than 2' and south of dec 30n
You can also search ngc, ic, and nearly every other catalogue - even more obscure ones.