Leaking Roof Help

Since I've bought my house, there has always been a pile of debris (pine needles, leafs, muck) on a corner of the roof. I finally got around to clearing that off. However, today when I went into the attic crawl space. Right above where the debris pile was, the OSB is saturated in a small spot and a couple of drips of water has wet the insulation. Does not appear to be severe. Some moisture has made it down to the ceiling drywall and has caused three small brown spots.

I've cleared the debris on the roof already. Do I need to do anything else for that spot in the attic? Or is clearing the debris going to stop the leak? I will put a dehumidifier up there for a couple of days to help draw out some of the moisture.

Attached is a few pics to help visualize. House was built in 2005.

Any help is greatly appreciated

Aaron

Click links below for water damage pictures.
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Leaking Roof Help