Need help with resignation letter.

Ok so i just got offered a job with a salary increase and better room for growth and I accepted it. The thins is i just hit my 3 months at my current job and will now be resigning. What is the best way to go about this, or how should I word the resignation letter?
WGU Complete: September 2014
Comments
My manager was really happy for me to be moving on as he knew I worked my ass off for my CCNA, but I've also heard some horror stories as well when I researched this question - good luck
Arthur Ashe
Yes I am sure as there is no room for growth. Although i can learn a lot, I will be stuck in the position I am now for as long as I work here. Only an IT staff of 5. The new job has an IT staff of 65, I get a 4 dollar pay bump. It is 20 min closer commute than the current job, and more room for growth as well as opportunities.
Based on the size of your staff you don't really need a resignation letter unless they specifically request it in writing.
Managers Name
Please accept this letter as official notice of my resignation as "Systems Admin" at ABC Corp. My last day of employment will be xx/xx/xxxx. I appreciate the opportunities I have been given while working at ABC. Please let me know if there is anything I can do to make the transition as smooth as possible.
Sincerely,
John Doe
I don't know, something like that..short and sweet. You can verbally expand upon your reasons if you like.
Think of the 2:00 a.m. test—if you were awakened in the
middle of the night because of a network problem and had to figure out the
traffic flows in your network while you were half asleep, could you do it?
Current goal: Dunno
If you are at a similar place then clean your desk out, get your personals, and delete your shares, accounts, and history before you resign. Try to do it when no one is around.
My last coworker who resigned was not able to get his own personal stuff. And he said everything was not sent to him.
Luck is what happens when preparation meets opportunity
The key to a resignation letter is to be as professional as possible, just in case things don't work out at the new position.