Whether you hire a professional guitar refinishing shop or decide to do it yourself, custom guitar refinishing is first of all an exercise in the art of wood finishing. It is also an equal exercise in the skill and knowledge of music necessary to insure that your wood finishing skills do not adversely affect the sound of the instrument being refinished.
Refinishing of an instrument designed and made to produce a certain sound requires a great deal of patience and experience in order to achieve the "look" that you desire. Refinishing a guitar can absolutely change the way the instrument sounds after the "look" part of the job is completed. Further, a guitar refinishing will most certainly change the instrument's "vintage" status, much the same way that a "restored" antique car is not the same as the original vehicle. The value of your refinished or restored guitar may be less than it was in its original condition.
The cost of a professional refinishing job for your guitar can vary greatly. A quality, professional guitar refinishing for a guitar body currently will cost anywhere from about $200 to $350. As you add more items to the project the costs can increase dramatically. Neck through finishes, vintage finishes, natural wood finishes, metal flake, and carved guitar finishes can easily take the guitar refinishing costs near $1000. Original design, color, and exotic finishes can take your final cost figure well into Rock-n-Roll Star money range.
Do it yourself guitar refinishing is generally not recommended unless you have lots of time and patience, along with an opportunity to practice your technique on another instrument. In fact, many will tell you that if you do proceed to refinish your instrument yourself, go acquire an old one to practice on before starting your "real" project. And don't be surprised to hear that a better option may be just to sell the guitar as is. The bottom line: Think carefully about what you are trying to accomplish with your guitar refinishing and restoration project.
That said, there are plenty of resources available if you wish to complete a custom guitar refinishing on your own. Two of the best are The Guitar Refinishing and Restoration Forum and Project Guitar Refinishing Tutorials.
Most custom guitar refinishing shops will gladly offer to show you a gallery of their work so that you can get a feel for the quality of their work, types of finishes offered, and types of instruments they have worked on. For professional guitar refinishing sources we hope you will check out the Custom Guitar Refinishing pages here.