I'm using a NEX-3 for macros and am learning as I go - I've posted a few macros on the site.
If you are trying to take macros with the kit lens then the minimum focusing distance is 9.8" or .25m. Based on a review, it states that the lens will capture an area of 3" x 2".
For "truer" macro photography, you'll want to go in closer than ten inches. There are no native NEX lenses that will go closer so I went the legacy lens route.
First, I used an extension tube with a Canon 50mm - focal plane is only a few millimeters and focussing ultimately done by moving the camera back and forth rather than with focus ring. Lots of work but fun nevertheless.
Next, I bought a true macro lens - Nikon 60mm Micro f2.8 - I can get as close as 2 to 3 inches without an extension tube. This allowed me to go outdoors for some macro shots. There are different focal lengths and depending on what you want to shoot you may want a longer focal length.
This response is the abbreviated path I've taken there's a lot more to consider but if you have any other questions, let me know.
Sony A55 w Tamron 17-50 f2.8, 70-200 f2.8; Minolta 70-210 f4, 50 f2.8 Macro,50mm f1.7; Manual Minolta 58 f1.4 and Rikenon 85mm f1.4