Well, you just need three things for the bike to run (More or less): Air, Fuel, and spark.
1. Did a pack of mice take up residence in your air filter box while the bike was sitting for a month? Don't laugh, I had it happen to one of my cars.
2. Do you hear the fuel system cycle when you turn the ignition key on. If the system doesn't pressurize, the motor won't run.
3. If you determine that the battery is indeed fully charged, I suggest you check for spark by removing the spark plug, leave the high tension lead connected, ground the plug and crank the bike. Do you see a spark?
Good Luck,
Cheers,
Dan K.