I'll start with the obvious reminder that storm water and runoff are probably a buildings worst enemy (even worse than pets!). I know it sounds like a no-brainer to say to clean the gutters, and ensure things drain away from the foundation, but, it is so often overlooked it sometimes makes me wonder. If I see moisture in a basement, more often than not, I conclude it's one of these problems.
A clogged gutter soon becomes a wet fascia board, and worse a wet basement, especially if the ground is downhill towards the house as they meet, which will likely be the case with a waterfall pounding on the same spot along the home each time it rains.
There are simple solutions to these problems, like cleaning, and extending downspouts, adding some dirt that may have settled or washed out, or even adding a drain tile system. It's mostly just a matter of remembering to check them, and addressing the problems quickly.