The Northeast 115 is a great list of mountains and you will have a blast doing it. Even though it's now been a few years since I was obsessed with the 111/115, it's kind of like going to and graduating from high school or college - there's always a part of you that stays connected to it.
Anyway, I did 'em between '93 and '97 and here is my year-by-year breakdown:
1993 - 20 Adirondack 46R peaks;
1994 - 20 Adirondack 46R peaks (40/115);
1995 - Hunter and Slide in Catskills during winter, all 5 Vermont 4K peaks in winter or early spring, remaining 6 46R peaks, 17 NH 4K peaks and 6 in Maine (76/115);
1996 - 21 NH 4K peaks, 5 in Maine and MacNaughton in ADKs for "extra credit" (102/115);
1997 - remaining 10 in NH and last one in Maine (113/115)
At this point, I had completed the list as it existed at the time and was assigned completer #317. A couple of years later, Spaulding and Redington in Maine were "promoted" to 4K status and Wildcat E was switched to Wildcat D. Did Wildcat D and Spaulding in 1999 and Redington in 2000.
Anyway, I've done some other lists in the NE and quit before I completed others. None really captured my imagination the way the 115 did. Only thing that equals/surpasses it in my mind is my current State Highpointing project.
Good luck. I always enjoy reading about young dudes getting into the mountains ... reminds me of me awhile ago.