Part 1: Strings Change
How to Change Guitar Strings
The first step to any great setup is to change your strings. This is vital to getting a proper setup. Old strings have bad tone and can throw off your intonation.
1. Start with the new low E string, and string through the back of the body (if you have string-through body) or the bottom of your bridge (ex: Tone Pros Style)
2. Once the string is through the bridge, run it up the neck to it's corresponding tuning peg.
3. Wrap the string counter clockwise around the post (minimum of two full wraps). At the end of the final wrap put the string through the whole in tuning post and pull tight.
4. Repeat this process for the remaining strings.
5. Now its time to tighten the strings by tuning them up. Turn each tuning knob clockwise until each string is tuned correctly.
6. Once tuned, its time to stretch each string by pulling them outward from the guitar. This helps seat the wraps of the string around each post and will stabilize the overall ability to stay in tune.
7. Clip the ends off, leaving about 1/2 inch of string sticking out of the tuning posts. Don't go to short or the strings will slip out of the posts.
Pro Tip 1: When you are "stretching" your strings, you aren't actually stretching the strings. They don't stretch. What you are doing is seating the string as tightly as possible on the tuning post. You are removing the slack in the wraps.
Pro Tip 2: Trim the string ends, so there is no string hanging off the headstock. The last thing you want is to poke you or anybody else. Those things are like needles.
Pro Tip 3: Play the guitar for 5 minutes and retune. Play for another 5 minutes and tune again. After three times your guitar strings should be in a pretty stable tune.
If you have any confusion about guitar string tunings or the name of each string, you can visit wikipedia's guitar tunings page.