How do I leave an almost-family company on good terms?

I’m 22 and I’ve been working at a nearly-family company for almost 3 years. It’s a small company - about 10 employees total and I take care of 90% of the office-related work. I’ve pretty much known my boss since I was born. My mom works there and a girl I’ve known since I was 6 years old does also.

I’ve made the decision to leave my job. It’s just time. I am ready to get out and do something new with room to grow, more people to be around, etc.

I’ve already have decided that I wont give just 2-weeks. I’d like to give my boss more of an advanced notice. Right now we’re in our busiest time of the year and I don’t want to leave the company scrambling to find someone to learn my duties. I’m not in a huge hurry to leave, but my personal deadline is to be out of there by or before October 31st. I think it is plenty of time to make a smooth exit without causing a tidal wave for the company. That gives me time to put together a new resume and find a new job.
Now that I’ve babbled on a bit I’ll get to the point - I’m not sure if I should write a letter, just sit down and talk to him or both? So how do I quit a job on good terms?

Sit down and talk to them, today. Give them the exact same explanations you gave us. They’ll understand, and probably give you their blessing.

I had a similar situation and did both - a sit down talk and a letter. In the letter I personally thanked my employer for all the excellent opportunities they had given me and said how much I’d enjoyed working there. I also gave three months notice. It all ended well and I am still great friends with everyone there. I hope your transition goes as smoothly as mine did.

Sit down and talk with them. Tell them that you need to make a change in order for you to grow. If they are the people you think they are, they will be happy for you.
When I was in college I had a job working for a Union Oil distributor in a small town. Things changed, and they could not give me the hours I needed. I talked to the boss (best boss ever!) who was a very well known man in this small town, about my problems. He told me to go look for a job that would give me the hours I needed, and told me to use his name as a reference.
Good luck!