Chances are you won't save anything, people without experience running a job site tend to waste the money they may save correcting mistakes in scheduling etc. If you want a well run job with the possibility of saving money your best bet is to find a general contractor you can trust.
That said if you can put in the time and energy required (you really need to be on site A LOT) it can be very rewarding. But DO YOUR HOMEWORK before you start, there is a lot more to it than people think.
Best thing is leave structure, plumbing, electrical, etc to the pros. Tackle things like finished carpentry, painting and whatnot yourself. Just as rewarding but you also know your home is sound.