[symmet]

I just went through something very similar. I had been working with a smaller company all through school and for a while after I graduated. The people I worked for were family friends and just great to have as employers. Then, I had the opportunity to join another company that I felt would allow me to do more of what I enjoy and had more room for me to grow, so I went for it. It was quite difficult telling my boss that I was leaving, no doubt about it. He offered everything he could to get me to stay, but in the end I knew that it was time for me to move on to something new.

That being said, here's a few tips that I think could help you.

1. Remember that this is business. That doesn't mean forgetting about the people involved, just that the most important thing in this situation is your career.

2. Do as much as you can to help the transition. The new company that I went to work for wanted me to start asap, but I was willing to give my previous employer 2 full weeks of my time since I did value the relationship and wanted to leave on the best terms possible.

3. Just be honest. While they may not want you to go, they should understand that this is what you need to do.

Good luck! Hope it all goes well.