Using a Rokinon 500mm f/8 Mirror lens with my Nikon D3000

So for Christmas my mom bought a new lens for my Nikon D3000. I had asked for a fisheye but she saw something about how this has a fisheye setting, which it doesn't but I don't think she knew that. Anyways, when it came in an instruction manual was not included. I have no clue how to use it with my camera. I've put in on, but everything is blurry and when i focus it doesn't take good pictures at all. Does anyone know a place online I can read on to see if I can get some good pictures out of this?

The manual is available for download at the Nikon link below.

Let me summarize the qualities of a mirror lens.focus is critical, but some of the clarity problems may be do to blur.since the lens only has the f8 stop, you will need a high ISO (like 800) to get the shutter to at least 1/500 th second for hand held shooting. Or use with tripod and cable release. The other issue has to do with glare. The large front aperature is subject to glare from bright objects to the side of the viewing angle. This glare tends to fill-in the shadow parts of the image and generally washout the picture. You should consider getting a lens shade.

this is a fun lens to use even with its challenges.