Different Types Of Guitar Strings
There are different types and gauges of guitar strings available today, with not only the different brands of guitar string and gauge/thickness, but there is also nylon or steel strings to consider also.
So the sound of what you want your guitar to make depends a lot on the gauge/thickness and choice of guitar string...
The higher the gauge number -- the thicker the string
The lower the gauge number -- the thinner the string
Higher gauged or thicker strings will generally last longer and will have a chunkier and fatter sound. As where thinner strings won't last as long and will have a much lighter and crisper sound.
Nylon strings are much softer and aren't really that common, and only used on an acoustic guitar, but are a lot easier on the fingers when first learning to play the guitar. Steel strings are the standard across the board for all types of guitars and produce the most full sound.
A tip: If you seem to be finding that your guitar strings are vibrating a lot or aren't ringing out properly, this is usually because they are slightly touching the frets on your guitar.
If you have this problem and keep having it, try going for a thinner gauge string and that will give your fingers more room to move on the fretboard!
If you want -- check out: http://www.stringsandbeyond.com/ as they specialize in selling guitar strings and as well as offer free shipping on some orders!
Here's a bit of brief guide to the different string gauge's and thickness
ULTRA LIGHT STRINGS
E|-------------|.008
B|-------------|.010
G|-------------|.014
G|-------------|.022
A|-------------|.030
E|-------------|.038
EXTRA LIGHT STRINGS
E|-------------|.010
B|-------------|.014
G|-------------|.020
G|-------------|.028
A|-------------|.040
E|-------------|.050
LIGHT STRINGS
E|-------------|.011
B|-------------|.015
G|-------------|.022
G|-------------|.030
A|-------------|.042
E|-------------|.052
MEDIUM STRINGS
E|-------------|.013
B|-------------|.017
G|-------------|.026
G|-------------|.034
A|-------------|.046
E|-------------|.056
HEAVY STRINGS
E|-------------|.014
B|-------------|.018
G|-------------|.028
G|-------------|.040
A|-------------|.050
E|-------------|.060