When you are ready to resign, the #1 rule is to remain professional at all times. Write a short letter of resignation and express appreciation for the opportunity to work with the firm and the people.  Bring that letter to your direct manager or supervisor if you are physically located in the same office.  Otherwise, email is fine with a follow-up phone call letting your boss know it has been sent.

Start the conversation with a simple statement – “While I greatly appreciate the opportunities and learning I’ve received here at xyz company, I’ve decided it’s time to move on. I’ve accepted a job at another firm. I want to make sure to wrap up everything I’m involved in here so there are no lose ends. That’s why my last day is x/x/14”. Two weeks is the minimum amount of notice you should give. One month is the new standard for job titles of manager on up.

As tempting as it may be to tell people what you REALLY think of them on your way out the door, please don’t do it! With social media, you will stay connected to these folks in some way forever, just by virtue of having worked together for some period of time. If you really need to get it off your chest, write a letter (AT HOME!) and don’t send it. You can symbolically let go of all your negative emotions towards the prior firm/boss by destroying the letter in whatever way most appeals to you.

The safest thing to say is “I wish you all the best”. No more is necessary. If you had a positive relationship with the person, ask if they’d like to connect via LinkedIn. If you were friends, see if they’d feel comfortable staying in touch on Facebook. And if you REALLY want to stay in touch with someone, perhaps because they’re well connected in your industry, make a definite appointment to meet for lunch/coffee/a drink/at an industry meeting etc. so that it WILL happen. If you both get it on your calendar while you’re still standing there, it’s much more likely to happen than if you try to play phone tag once you’re gone.

Next, make sure that you tie up as many loose ends as possible before you leave. Completely turnover any undone projects to their new owner and document instructions on those items you’re transitioning. It’s always a nice gesture to make yourself available to that person for a week or 2 after you leave, in case any questions arise.

The last 2 weeks on the job are critically important, because you have the opportunity to influence how you are remembered by your key contacts at the firm.

Hope that helps!