There are several approaches you can take. Many people on the forum use extension tubes. The most widely used are the Kenko because they support AF and auto exposure. Kenko tubes are rather expensive and a set of three will cost you around $170,
http://www.bhphotovideo.com/bnh/controller/home?O=search&A=search&Q=&sb=bs%2Cupper%28ds%29&sq=asc&ac=&bsi=&ci=276&shs=&at=Brand_Kenko&basicSubmit=Submit+Query .
Another option is often called close-up filters; they are not filters in the strictest sense but true auxiliary lenses. They are called filters because they attach to you cameras lens by screwing onto the filter threads, and to avoid confusing them with true Macro Lenses. I got my set of 3 52mm lenses at Ritz Camera for less than $30; you can pay more than $100 for something like the Canon 250D lens.
You can use the same close-up filter(s) on either of your lenses.
This was with the close-up filters.
Nikon D50, 55mm, 1/1500 sec - F/11, 18-55mm, ISO 400 I’m sorry but I didn’t note which filter I was using. The nymph was about 1/8” long, sitting on a rose. A flash was also used.
This is a crop from the same picture.
Another picture taken with the aid of a close-up filter
Nikon D50, 1/90 sec - F/6.7, Auto Flash: Built-in TTL, 50mm F/1.8 D, ISO 200. This was with the +1 diopter filter.
The 50mmf/1.8 is a very popular lens, partially because it only costs about $115, plus it is very versatile (makes a good low-light lens and it can be used several ways for close-ups). You can reverse the lens and mount it on the camera with a reversing ring, like the Nikon BR-2A, which runs about $30. You don’t really need a Nikon ring, after all it is just a metal ring with threads on one side and a lens-to-camera mount on the other,
http://www.bhphotovideo.com/bnh/controller/home?O=search&A=search&Q=&sb=bs%2Cupper%28ds%29&sq=asc&ac=&bsi=&ci=3065&shs=&at=Mount_Nikon+Auto+Focus&basicSubmit=Submit+Query . This setup with the 50mm lens will get very close, but everything (focus and exposure) will be manual and that is why the 50mm is the lens to use – it has an aperture ring so you can set the aperture.
Another possibility is a Macro-coupler. With a Macro-coupler you would mound your kit lens to the camera and mount the 50mm lens reversed to the front of the kit lens. This has the advantage of having auto exposure since the camera can control the aperture. The DOF is going to be so narrow that AF may not be possible. A Macro-coupler will cost about $8,
http://www.bhphotovideo.com/c/shop/3066/Macro_Close_Up_Equipment_Macro_Couplers.html
Nikon D50, 46mm, 1/160 sec - F/8, 18-55mm F/3.5-5.6 G, ISO 800, and I was holding the 50mm f/1.8 reversed against the front of the “kit” lens with my hand – this is very awkward to do and you are likely to drop the lens, I did.
This site has a lot of good information,
http://www.earthboundlight.com/phototips/closeup-macro.html
--
Brooks
http://bmiddleton.smugmug.com/