Roads
So you have all your little tidbits over here and forests over there, but you have no way to connect them all together. The most obvious decision would be to create a road. And that's what we're going to do. So first, on the RollupBar, click on the Misc button and then select road. Then click where you want your road to begin and then move your mouse to the next point (the road will curve automatically). As you can see the road is being built as you place points. Awesome, huh? Double click on your final point to make the road complete.

This road is great and all, it's visible and great and curvy... but it doesn't exactly look like a road. So let's put a road texture on it. Make sure your road is selected and go View > Open View Pane > Material Editor. Navigate to Materials > Terrain > Roads in the directories and then select road_concrete_one_stripe - and then click the top left button 'Assign material to selection'.

There, you've done it! You've added a road. Good job! If ou want to edit the width or anything, look in the Road Params on the RollupBar. That will provide you with everything you need.