Or if you're like me, you could sculpt for a few weeks, take a long hiatus, and come back and finish your project.
My quick advice -
stick with your original design! (I've spent countless hours redesigning mid-sculpt)
build a REALLY solid armature - this cant be repeated enough!
look at LOTS of reference materials (this forum is the best starting area).
Be patient
Also try to remember its not a race, just enjoy the process
Have fun!