I understand what apeture is and what shutter speed, but what I don't understand is how, why and when I need to synchronize the two. I do manually adjudt my shutter speed, but have never done anything with the apeture. I lost my cameras manual quite awhile ago. Another question I have- I remember my manual have instructions on how to blur the edges of an image to make it look like it had a dream like quality. Can somebody tell me what setting I need to use to accomplish this?
... is all about controlling the amount of light that hits the film. There are 2 ways of controlling that light: the duration the film is exposed to the light (Shutter Speed), and the size of the opening in the lens (Aperature). Exposure is all about controlling the balance between those two controls. The smaller the aperature is, the longer the shutter has to stay open (or the slower the shutter speed has to be) and vice versa.
Now, there are some considerations that control where you set the balance point. If you're taking an action picture where your subject is moving, you need a fast shutter speed or else your subject will be blurred (sometimes, as with waterfalls, you may want the blur, in which case, you'll want to intentionally slow the shutter speed down).
But, there is a trade off on the aperature side too. There's an aspect known as "depth of field". When the lens is focused on a given subject, the depth of field is a measure of how far in front of and behind the main subject will also appear to be in focus. It just so happens that, the smaller the aperature is, the greater the depth of field will be. So, for scenics, you generally want to have a large depth of field (so most of what is in the frame appears to be in focus), so, it is best to shoot with as small an aperature as you can for maximum sharpness. To do so though, and have the correct exposure, you need to "compensate" by having a slower shutter speed to let more light in. But, if you don't have the camera on a tripod, and the shutter speed gets too slow, you'll end up with a blurred photo due to camera shake.
The 3rd factor that plays into a correct exposure is the speed or ASA rating (or Exposure Value (EV)) of your film. The faster the film is, the faster your shutter speed can be for a given aperature setting (also known as "f-stop" by the way). From this, you'd think it would be best to always use the highest speed film you can get... then you could use small aperatures for good depth of field AND fast shutter speeds for nice, crisp, well focused shots with minimal camera shake. Alas though, generally speaking, the higher the film speed is, the more "grainy" it is. Therefore, you're pictures won't look as sharp because the film itself will have lower resolution.
The "blurred" effect that you are referring too (from your camera manual), I believe was referring to the depth of field. If you use a large aperature, and focus carefully on your subject, the rest of the objects in the frame will tend to blur out. The result is that your subject really stands out from the surroundings. This is especially useful for portraits, closeups of flowers, etc.
In my case, I normally shoot 100 ASA film (relatively slow) to minimize the grain, usually shoot (landscapes) with an aperature setting (f-stop) of about f11 or f22 (the larger the f number, the smaller the aperature), and therefore, depending on light conditions, a fairly low shutter speed -- typically 1/30 sec or slower. Which is why I usually use a tripod.
Hope this was clear enough. Feel free to ask more questions!