Choosing a Replacement

This Is a first for me, I have built a nice stable LAN, my users are all generally happy, I get very few newbie questions. In general a dream gig. but know it’s time for me to move on (wet eyes of sadness). After all my hard work I don’t want somehack tecky comming in and messing things up. I am looking for a dicussionon selecting a replacement, and a source for pre-employment tests. After all running a mixed Win Nt4 and Win2k lan is not always a cake walk. Any thoughts? Cheers