Will these lenses fit my camera?

Will the Nikon 50mm f/1.8D AF Nikkor Lens

AF-S NIKKOR
50mm f/1.8G

or Nikon AF Nikkor 50mm f/1.8D Wide Angle

fit my Nikon D5100?

i read somewhere that some of them won't fit?

They will all fit your camera.

Where did you read that Nikkor lenses will not fit a Nikon dSLR camera? Don't believe a thing you read there again.

You seem to have some misconceptions when it comes to lenses.

"Nikon AF Nikkor 50mm f/1.8D Wide Angle " It is in fact a medium telephoto lens on your D5100

The lenses you need if you want to shoot using auto-focus with your entry level camera are the Nikkor AF-S lenses. They have the internal auto-focus motors needed for your camera

If you do not mind manually focusing your lenses, any Nikkor AF lens will work. You can use the cameras light meter with them, but will have to use the electronic rangefinder in the cameras viewfinder.

If you do not mind doing everything in manual, you can use any Nikkor AI manual focus lens. When I say everything manually, I'm really talking about using an external light meter to determine the proper exposure.

Fhotoace is basically right. Still,

See the following, scroll down and click the technical specs tab.

http://www.nikonusa.com/...D5100.html

It says the lens mount is a "Nikon F bayonet mount." Any lens that is a "Nikon F bayonet mount" will fit on the camera and can be used.

However the D5100 does not have a built in autofocus motor. This means you can use any of those lenses but none of them will have autofocusing capabilities. As a result you must buy lenses that have autofocusing capabilities built in. If you buy modern Nikon lenses with built in autofocusing capabilities they are denoted by AF-S, "S" for "silent wave motor".

Scroll down more and see the "Compatible Lenses" section.

It reads:

Type G or D AF NIKKOR: All Functions Supported Except Autofocus.
Type D PC NIKKOR: All Functions Supported Except Autofocus and some Shooting Modes.

There's other compatibility information that explains which features will or will not work with which types of other lenses.

As a side note technical specifications is the only thing I would read and believe on Rock Kentwell's website. He's an engineer and a brilliant cynical troll not a professional photographer. Other than technical specifications I would only look at his website for comedic value. At a first glance his site is really helpful but then you learn about commercial photography and how to identify the senseless drivel in between useful information.