Firstly hope your enjoying the bike
Secondly preload and damping are different things, in short preload deals with distance and damping deals with speed.
Preload is the starting point from which the suspension can compress, it has a limited amount of travel (obviously) if you carry a heavy load with less preload you risk compressing the unit completely (bottoming out) and putting extra stress on other parts of the bike. That's why it is recommended when carrying extra weight to increase the preload.
Damping changes the speed at which the suspension compresses, less damping bounces faster more damping makes the ride essentially harder. If I was taking the bike on a track day, I might, with the advice of others increase the damping to make the ride a little less bouncy. To be honest though there's no real need to change this, it's setup well enough for road riding.
When I first got mine I wound the preload down as far as possible to make it as low as I could. You will find that after a while the suspension "settles" a little. After 1500 odd miles I've experimented with winding it up a little, but found maneuvering to park (especially in the wet) quite difficult.
I took my girlfriends dad out for a ride last weekend, I made no adjustment to the preload (probably should've but it was a only a 15 min bimble) the bike didn't bottom out, but ran very low at the back, so much so I could finally get both feet flat on the ground.
If I was going to be doing a long journey 2up or with luggage I would load up sit on the bike give it a bit of bounce so the suspension can settle and gauge if it needs more/less preload, adjust and repeat until I'm happy.
Btw, I've garnered my limited knowledge from reading Bike magazine, if you're new to biking it's a good read, this month they took their F800GS round Ireland, which I'm hoping to do later this year.
Hope that all helps.
Jolyon