How to take a macro shot?

If I put my camera on the A dial how do i take a macro shot? I have a nikon 85mm f3.5 macro lens
Do I need to lsmaller aperture or bigger aperture and what ISO and shutter speed do I need to put it on?

Added (1). Thank you so much for the help! Great responses i will try it

If you are in A mode (aperture priority) then all you need to do is set the aperture - the camera wil set the rest.

You only need to set all three parameters if you are shooting in manual.

For macro shots, you want a fairly small aperture (f11 or f16) to get the most depth of field - even then you may not have everything in focus as the camera to subject distance is very short and this also affects depth of field.

You almost certainly want to use a tripod too, as any camera shake is magnified by macro (1:1) lenses.

The nature of macro shooting. It is to get as "close" to the subject as possible, thereby magnifying the subject in your viewfinder. The one thing that really distinguishes the macro lens is the close focusing ability. On your lens it is about 30cm.

1. I highly recommend setting the camera on a tripod. Working at such close distances is difficult, making minor adjustments on a tripod is more accurate than dealing with shaking hands and body (this movement is magnified and often visible in hte final picture, when shooting from close distances).
2.assuming, you are using a tripod, turn off VR.
3. Compose and Focus. Manual focusing is preferable here. The computer will make a reasonable estimation, but it is sometimes off. Set your camera to live-view mode. Magnify on the area you want sharp. Focus manually. Turn off auto focus.
4. Set an exposure. Since you are on a tripod, use the lowest iso possible to retain quality. Set an aperture that suits you. Usually F8 - F11 when I shoot macro. You may want more for more dof, or less for less dof. In "A" Mode, you can let the computer decide the shutters speed.
5.use a remote or the 2 second timer. At this moment, the less you touch your camera the better. The two second timer or the remote will give you plenty of chances to move away from teh camera and avoid touching it during the picture taking process.