It's very simple - go to Google Maps (eg. UK = http://maps.google.co.uk, US = http://maps.google.com). The link is also available from the Google home page amongst the Google links at the top left.
On the Maps page, put in the number or name of the house/farm (if known), street name and the area you're interested in and, all being well, you'll see a conventional map appear with a marker showing the location of (or close by) the property. You may also see a preview of the street on the left of the map, which can be clicked on to reaveal the street in the larger pane.
If you don't get the preview, then grab the little yellow 'man' icon above the + (plus) sign on the zoom bar and drag him with your mouse to the marker on the map. You need to place the 'man' icon onto a road which becomes highlighted in blue when you drag him onto the map. The street view should now be visible.
To turn around, hold your left mouse button down on the image and drag it from side to side to suit. You can also drag the mouse up and down to view taller buildings. To move along the street, just click on the white arrows which should appear on the road.
To return to the map, click the - (minus) sign on the zoom bar a couple of times. You may find you'll want to zoom out a bit further when the map is displayed once more.
[Why Mappy Monday? This phrase has been included in the title in order to take part in Daily Blogging Prompts at Geneabloggers]