Do you have any tips for someone changing jobs after more than ten years?

I’m in a career that requires an advanced degree and special certifications and licensure, and have been at my current job for over ten years. I’m looking to transition to a different type of position within the field but I’m out of touch with the job transition formalities of today.

After being with the company for so long, I have four weeks’ vacation time, and in the past people were expected to give as much notice as they had in vacation allotment – is this still the case? Personally, I think that amount of time would be good for my current employer to arrange coverage and possibly hire a replacement for me. But would an employer wait that long for someone new to start?

I’m wondering if anyone else has been through the process recently (whether job seeker or hiring new staff) and would share some of their experiences, advice and tips with me, as well – especially if they are in a highly specialized career, like academics, health care, scientific research, etc. Thanks!!