Hi Emily,
If you are in North America then you are asking at just the right time.
If you have no other races planned then you can take a few weeks to be
active without regimen. Spend the time doing the things you enjoy -
with no real structure. This might be a good time to look at core
strength and taking an abs class at the Y or something like that. Get
the mountain bike out - maybe some train running. Just enjoy.
During the last week of September/ first week of October start
researching. Contact coaches and ask them what their general
plan/philosophy is. The more you know about different types of
year-round training the better you can make a choice about the type of
plan you want to follow.
When the middle of October rolls around it's time to start thinking
about the year ahead and making an actual plan. Once your mind is
fully engaged in triathlon again, it will be time to start following
the plan.
You'll need to figure out for yourself how many hours a week you want
to train - and if that number will fluctuate as you get closer to race
season. How "serious" do you want to be - do you want to include club
rides or rides with friends - or are you going to be solo?
Knowing what you want your lifestyle to be like, and what your goals as
a triathlete are, will help you pick the right plan and/or coach.
My personal experience (as previously posted) is that a single "peak"
is very difficult - it's hard mentally to watch your peak fade, and it
sucks if your "A" race doesn't workout.
-CF