Caulking is considered the most beneficial of all home projects. It
will help eliminate drafts, insects, water, noise and dust and save you
money too. The cost is small and it won't take a lot of time. So let's get
started...
There are a couple of caulks that we could use. The regular latex
painter's caulk is easy to work with. It cleans up quickly with water and
is very inexpensive. I prefer the slightly more expensive latex based
silicone caulk. It is easy to work with and also cleans up quickly. The
silicone caulk will remain flexible a while longer and is very good at
repelling water. Both caulks are paintable. You could use either one with
great results!
The goal is to seal all the openings that water or air could enter. One
place is around pipes:

Windows and doors are notorious:

The siding where the boards meet:

To prepare the tube you need a utility knife to cut the spout at an
angle. It's best to try a small bead first. The larger the crack or hole
the larger the bead. Have on hand a damp cloth to wipe away excess. I use
my finger for a professional look.

Once you have finished wait till the caulk is dry and then you could
paint to match. I check back every year or so to see if the cracks have
returned.
In addition to saving money you will have peace of mind knowing your
house is the "Caulk of the Town."
And so life goes on a little better now...