Wide angle lens/macro/fisheye for Nikon? Explanation please?

I'm new to DSLRs, and I have a D5000 which I would like to use for very wide shots. Not sure if I'm describing the correct thing, but basically I want to mimic shots that are very close to people, for instance, where distance, as well as the entire photo, is exaggerated.

I hear lots of mixed terms, such as macro and wide angle, so I want to make sure I'm talking about the correct thing before I buy something.

I also see lots of wide angle adapters and fisheye filters and what not… I'd just like some clarification please as to what does what… And if anyone could tell me what exactly I'm looking for to get the shots I was describing above, that would be great, whether it's something you screw on the end of an existing lens, or completely different lens you mount… Not so sure about anything really. Thanks!

P.S. I have an 18-55mm kit lens with 52mm threads, if it matters at all. I always choose a best answer, and here I would really appreciate some input… Thanks a lot in advance!

Wide angle lenses are just that. They can cover up to 110 degrees of view and do NOT cause aberrations at the edges of the images

Samples using a 12-24 mm lens

A fisheye sees the world in a 180 degree view and by design have barrel distortion.

Sample:

A macro lens is one that can shoot closeup images at 1:1, 1:2, 1:3 and 1:4 image to subject ratios with edge to edge perfection with NO aberrations.

Anyone who attempts to sell an add-on lens that claims to be all three and calls the lens a "professional" lens is flat out lying. Someday they will have to specifically list the features and limitations of such a device and leave the word "professional" out of the ad copy.

The total cost of the three lenses is about $2, 600, a far cry from the $40 asking price for this toy

Macro lenses are used for showing a lot of detail of very close up subject (less than 12 inches). Wide angle lenses will allow you to view more in the picture, if that makes sense. Fisheyes are very wide angled lenses that cause a lot of distortion (make things in the center big and shows more than a normal lens). They will make a normal, boring photo look really awesome. For what you want to do, I'm guessing you need a wide angle lens or maybe a fisheye based on your person preference. I hope this clarifies some of your questions.

I'm including links of examples of macro, wide angle, and fish eye photography (in that order):
http://www.bestpicturegallery.com/Best_picture_gallery_macro_photography_thistle_om.htm
http://www.digital-photography-school.com/17-stunning-wide-angle-images
http://www.juzaphoto.com/eng/articles/sigma_8mm_fisheye_15mm_fisheye_review.htm