I found this nice video about showing subjects focused and the background blurred or viceversa
However, its for video only, the question is how to make it for pictures?
By referring to "subjects focused and background blurred or viceversa", I believe you are looking for the effect produced by a shallow depth of field.
Large aperture lenses will give you this effect very strongly, but you can probably still achieve it (albeit to a smaller degree) with the lenses you may already have.
The easiest way to see this effect is to:
1) zoom to the longer end of your lens if your lens is a zoom
2) set your camera to aperture priority mode (A or Av), if it allows this and dial the aperture to the lowest number on the camera (often something like 6.3, 5.6 or lower)
3) move as close to the subject as your lens will allow you to while still focusing
4) take the picture
This will give you the effect shown here.
You can manually focus to the foreground using an aperture like f/2.8 or wider. That will create the in focus subject and blurred background. It depends on what camera and lens you are using to do this.
You can use a 'Lightfield' camera like the Lytro which lets you take a photo with multiple layers of depth.
There are some very clever 'hacks' to make similar photos by filming static scenes with DSLRs and adjustable focus however this is tricky and obviously doesn't work for moving scenes.
You'll have to be more specific with what you want if you want more detailed answers than that though i'm afraid.
This might also help for manual focus in the Nikon P510
You can't select the focusing mode from the side zoom, only vary it in the MF mode; so you should always select the focusing mode from the selector (flower icon); for example, if you have selected MF for P mode, when you start again the camera or go into shooting mode the P and MF appears left side up the display; you press OK and the focusing vertical gauge appears on the right side; now you can go up and down it from the side zoom if you have selected MF for it from the menu. For me it's quite enough, because I wanted all the time directly use the selector, thus actually trying to set the flash (up) or to select another focusing mode (down).