I have seen plenty of landscape shots online and in books that have enthralling foreground and awesome background. At many places, I have read to get close to the foreground. I understand that, however I am still confused on how one positions the camera in such scenarios. Should I point my camera down (towards the foreground) or just keep it in line with the horizon?
Generally speaking, if you want to bring the viewer in to a landscape scene via the foreground, vertical format works particularly well. It is still possible to capture close foreground in a horizontal format, but the effect is somewhat lessened. Ultra-wide focal lengths, such as 10-12mm for APS-C format cameras or 16-18mm for full frame cameras, are particularly useful when bringing in the foreground of a shot.
To really get the viewer right up close, its best to keep the camera low to the ground, and very close to the initial foreground object you want to capture. Some examples might be a decrepit old log, the stones lining the shore of a lake, or even the edge of a lake itself. And by close, I mean as close as you can get and still maintain clear focus (which might be only inches from the closest element of your foreground.) You will usually want a fairly narrow aperture to encompass as much depth as you can. If you have a higher resolution APS-C camera, you can get away with around f/8 without losing detail, and f/11 with some softening. A full-frame camera will usually be pretty sharp up through f/11, and f/22 with some softening. If you have a DOF preview button and live view, that is usually the quickest way to set your aperture to the most ideal setting. If you don't have such a feature, you can try a hyperfocal calculation to determine which aperture you should use to maximize your depth of field. (Keep in mind, however, that you might encounter diffraction softening earlier with higher density sensors.)
If you want to maximize the potential of capturing wide-angle shots, you might try using a full-frame camera and a 17mm or 24mm tilt-shift lens (Canon offers all of these items.) With a tilt-shift lens, you have more freedom regarding aperture, as the tilt feature will make it a cinch to get your entire scene from foreground to background in clear focus.
As a final note, many ultra-wide angle landscape shots, particularly those that include a lot of foreground, often have a very high dynamic range. The band of sky at the top of such a scene will often blow out when exposing. A very useful tool to add to your kit is a filter system like the Lee Filter System, and some solid and graduated ND filters. Solid ND filters will allow you to expose for a lengthier time and achieve those types of scenes with glassy-smooth water and motion-blurred clouds. Graduated ND filters will help you balance your scene contrast, and capture all of the detail present in those bright skies (or, for that matter, when used upside down, capture the brightness of desert sand against the darkness of background mountains). You should have a variety of filter densities as well as gradations (hard vs. soft) to accommodate the widest variety of scenes. A tripod is essential if you intend to capture longer-exposure wide-angle landscape scenes.
Use a tripod and get the camera fairly low to the ground (not always necessary depending on what you're photographing). Work out what focal length (20mm etc) you will be using and calculate the hyperfocal distance (this involves various figures in the calculation, alternatively there are Android and iPhone apps available which will do this for you when you input your settings and lens)
The hyperfocal distance will let you set your focus range to the correct distance setting (you switch to manual focus for this technique) with an aperture which will give you the maximum front to back sharpness (typically landscape photographers tend to go to about f/16 - much further past this and you start degrading the sharpness with the effects of diffraction). It will also tell you how far away from the sensor the closest object has to be to achieve sharpness.
Typically using a wide angle lens you will need to point the camera down somewhat to get the foreground framing you're after but ultimately you need to change the framing depending on the composition you wish to achieve.
This is kind of a hard question to answer with the details you have given, but I will give it a shot.
It sounds to me like you are trying to keep the foreground in focus and blur the background slightly to give emphasis to the immediate objects near the camera. To do this you can set your camera to Aperture priority mode(Av) and open up the aperture to its largest value, for example f/3.5 or smaller. Then focus on the foreground objects, and recompose to include the landscape as you wish.
It might also in this case help to have a longer focal length lens to enhance the effects of compression. That would require you not to use a ultra-wide angle lens, but possibly a mid range zoom or mid range length.
Another thing that will help you is to get down low! Either lay on your stomach or use the cameras live view function to hold the camera as low as it can go! You can also use a tripod type object such as a bag of rice or shoot sac.
You can use a telephoto lens to bring the foreground into your frame. This post might be of some help Digital Photography School
Like dpollitt said, your question is kind of vague without more details.
You should get close to the foreground with a wide-angle lens because they tend to magnify objects closer to the lens. For the exact same reason you want to use a tele lens from far away when shooting portraits: Otherwise you would get a large nose and chin with some hair in the background...
I have little experience with wide-angle lenses, but I never came across a rule that says you should keep in line with the horizon.