Resigning well?

I have recently returned to nursing after a lengthy absence in which I let my RN license lapse. There is a story behind this, but essentially instead of my licensing body making me take the RN Refresher course, I was allowed to return to work as a RN with a restricted license. Thankfully, I was able to secure a job in which my restrictions could be met, and they have long since been removed so that I now am free and clear to practice as a RN.

My return to work went much smoother than anticipated, other than having to deal with a challenging co-worker at the outset. The physician I have been assigned to is both an excellent doctor and a kind person, and I have become friends with the rest of the staff. While the job itself is the least challenging position I've ever held, I've appreciated that as it's really been quite an effortless transition back to the workforce with minimal intellectual load. That's allowed me to focus what little time I have left at the end of each day on my children and husband.

Recently I was offered a job. Not just any job, but my dream job, working in a specialty field that I am very interested in. I had been taking courses specific to this potential field after I had let my RN license lapse, and had been planning to either open my own business or knock on doors heavily this fall once the temporary position I'm in now ended. But I've been approached by a specialist who wants me to start before my current position ends, and honestly, I would be a fool not to accept this position. Not only is it in the career track I want to take, but it will also allow me to participate in research, and potentially regain my NP license (which I also let lapse in order to raise my children). Additionally, it means that I can be home with my kids for most of the summer, as well as before and after school, which has always been important to me and is the sole reason why I gave up my licenses initially.

But...I realize that leaving this position has a cost. I like and appreciate the staff enough that I really want this to work for them. I don't in any way want to leave my doctor (or the other staff) in a bind. There is no employee handbook at this facility, so there is no "specified" amount of time required for a resignation. However, my initial contract stated that if the incumbent were to return early, I would receive 30-days' notice, so I am planning to give four-week's notice with the option of providing them with a fifth week if the need arises. Aside from that, are there any other issues I should be considering as far as making their transition to another new nurse smooth? I've already written out a detailed listing of my daily duties, as well as a list of "extra" things I have taken on since starting there. I'm also going to update the package I was given when I started that contains helpful job hints, essential billing/treatment codes, key phone numbers, etc. I guess what I'm asking, is how do I resign well from an organization that essentially took a chance on me and gave me my RN license back?

I welcome your thoughts.