One of the most common mistakes beginners make when tackling complex 3d modeling tasks, is wanting to hit a home run, right off the bat. They expect to find a magic command that will get the work done in one shot. That is rarely possible.
Because they don't try to differentiate between "An Assembly" and "A Part." You might be able to model parts in one shot, if they're simple enough. But that one shot approach will only drive you nuts if you try to apply it to an assembly.
So the first task you should perform for modeling a guitar, or any assembly for that matter, is to make a list of all the parts. Then you can tackle one part at a time.
Here's a preliminary, quick list of the parts of the guitar you will be learning how to model here, from the website...
- Body. The part of the guitar that looks like a beautiful, rounded, female shape.
- Strap pin.
- Finger board.
- Head stock.
- Machine Heads and Tuning Pegs (an assembly).
- Strings (I almost forgot to include this -- fun to do since we can get the diameter dimensions easily).
When you get overwhelmed by a project always remember the key to success is to "Divide & Conquer."