I've got Mac OS X Snow Leopard with an Intel SSD. There are rumors that things like cache files are bad for SSDs. What kind of settings should I check out to make my SSD live long and well?
Not really a problem any more. Wear-levelling algorithms in modern SSDs mean that they will most likely outlast any HD with the same write load. Because of the lack of TRIM support in many major OSs (Win XP, Mac OS X), drive controllers have been getting much, much better at doing garbage collection themselves, to the point where enabling TRIM support can make some models slower!
From reports I've seen, the Intel drives do like TRIM, and there is a nice tweak app to enable it on OS X (Apple only supports it on their own SSDs offcially). Please read the comments on that article before deciding to do the tweak. OS X Lion will add support for it on all drives.
The biggest factor affecting modern SSD performance is how full the disk is. This is a side-effect of wear levelling and GC - the more free space you have the less cleanup it needs to do. Filling your disk up will often cause a massive slowdown - great example and analysis here.