[Sgran]

First of all, it's good to keep moving during your career, especially if you're young. If you're not sure you're going to like your new job, my best advice to you is to fight the urge to let your lifestyle rise up to meet your income. Once you take on car and mortgage payments, etc. you're stuck where you're at until you can find another job at the same level.

As for resigning: that's part of the game and everyone knows it. Be straight with your boss and give proper notice. No more no less. They'll understand.