Welcome to 996 world! If you're not already, you should get familiar with Rennlist.com and Renntech.com because they have a lot more 996 activity than this board. You'll learn fast with them.
Next, change the oil and drive it! Tell it that its days as a garage queen (25K miles in 7 years = about 3,600 mi/yr) are over. The story goes that the cars most likely to have IMS problems are the ones that see very little use. My theory is that since they don't get driven a lot, their owners don't bother to change the oil more often than the factory's suggested interval (15K miles), which is definitely a no-no.
Rennlist and Renntech can give you an idea of some of the common failure areas, but one thing you should do to start is upgrade the radiator cap to the latest part number, since the original ones are known to leak coolant.
Until Wayne's book comes out, this is a nice little bit of light reading:
Amazon.com: Porsche 996 The Essential Companion: Supreme Porsche (9781845840969): Adrian Streather: Books