Beginners Guide to Guitar Effect Pedals

Almost since the invention of the Electric Guitar, musicians have been using electronic devices to modify the sounds created by their instruments. These days there is a vast range of effects units available, both hardware and software based, which can create a dazzling array of sounds. Despite this, there are still a few core effects which continue to provide the staple diet of most guitar players.
Distortion
This effect relies on overloading the signal, so that the waveforms become distorted, or "clipped". This means that smooth sound waves become squarer, making the original clean guitar tone more "gritty" or "dirty". The effect was originally achieved by literally overloading guitar amplifier inputs, to an extent that the electronic components, usually valves, were unable to process the signal properly.
Delay
There are different types of delay pedal, ranging from the short "slap-back" delay popular in Rock & Roll and Rockabilly styles, to the longer "echo" delay favored by U2's guitarist "The Edge" (Dave Evans to his mates). The classic method of getting these results is to use a vintage Roland Space Echo.
Chorus
This effect is interesting because most non-musicians aren't even aware it exists, but in the 1980s it was all over just about everything! For one of the most famous examples, listen to anything by The Police from the late 70s/early 80s. Andy Summers used the effect on just about every track, and along with Sting's vocals and Stuart Copeland's idiosyncratic drumming, it formed part of The Police's trademark sound.
Wah-wah
This is one of the most recognisable guitar effects - just listen to the opening riff of "Voodoo Chile" by Jimi Hendrix for one of the best examples of the wah-wah sound. It gets it's name simply because it sounds like a person saying "Wah wah wah"! It was invented by Vox while creating an electronic filter, and basically works by filtering out particular frequencies in the guitar signal, based on the position of a foot pedal. The guitarist plays the guitar normally, and rocks the pedal to move the filtered frequency around, creating that distinctive sound.
That should give you an idea of what's available, and what it does. But don't forget, no amount of effects will cover up bad playing! You need to get stuck in and practice. And if you're serious about your playing, you really want to look into some proper tuition.

There are some superb Online Guitar Courses available these days, which represent superb value for money when compared with private tuition. They're probably cheaper than all the books and DVDs you could end up buying,too! If you want to improve your guitar technique, and are serious about your playing, you owe it to yourself to look at them.