Hi!
Understanding aperture and shutter speed is very important for any photographer who wants to capture more than just family album photos using only the auto-setting.
A lot of info can be found on the subject either on the Internet (try Google for instance) or in basic photography books which you could find in the library. One word you should look for in addition to shutter and aperture is exposure!
The one article that I read first (and was quite baffled by it at first) is here:
http://www.photo.net …king-photographs/exposure
It is quite technical, but you should get the hang of it pretty quickly.
Basically the aperture controls how much light reaches the sensor in the camera. The smaller the f-number, the larger the aperture and thus more light on the sensor.
The shutter speed controls for how long time this amount of light affects the sensor. The shutter allows the light that has passed the aperture-hole to reach the sensor. Shutter speed defines the time that this shutter is open (for instance 1/30 means 1/30s =0.03s). The smaller the number (notice the division - 1/30 is actually bigger than 1/100!) the shorter the time.
The longer the shutter speed, the more chance for your photos looking "shaken". That's because as your shutter allows the light to reach the sensor for say 1/30 seconds, the scene in front of the camera has that much time to change (the most change occurs because of the shaking of your hands).
These two are interrelated in an interesting way. If you want to have a dark picture you either want less light on the sensor - OR you want less time for it to affect the sensor. So either you make the aperture smaller (the f-number larger) OR the shutter speed faster (e.g. from 1/30 to 1/100). The same applies for lighter images - just vice versa the above.
The auto-settings will calculate a nice balance between these two numbers based on the amount of light available, your preferences (exposure setting - lighter/darker), the ISO-number etc. If you want to control all the settings, all of these should be taken into account.
Finally relation between shutter speed and aperture is the basic thing to understand. But that's not all there is to it! Shutter speed, aperture, and exposure are also related to for instance ISO-values and depth of field. So you'll have a bit to learn, but don't worry, it's not too complicated. Once you'll learn it it's very easy!
And hey, the most important thing to do is to explore the different effects of these settings using your camera! Hope this is of any help.
v