Another post about it here:
is-experience-needed-95475.htmlAs I posted there, it would be a significant handicap for you if you apply with zero working experience. In fact, some schools like Tuck prohibit those with less than 2 years of working experience from applying.
Even top business schools that are known to be more lenient towards younger applicants have average WE of 4 or more years.
If you really want to apply early, then I suggest you find a job (that somehow relates to business) and stick with it for at least 2 years.
If you have the time and money to waste, came from a top undergrad, perfect GPA (3.8 at the very least), perfect GMAT plus endless awards and connections then maybe you can try applying now. (I believe it also helps if you were successful in making your own start up company) Again, this is for the top business programs. There are probably programs out there that don't rely heavily on WE but that's not the case for the top tier schools.