I'm a firm believer that everybody should get out their truss wrenches and wank away at your truss rod, observe what it's doing to the shape of the neck. Overtighten it [a little] to see how the neck takes backbow, etc. Unless you attack it like an idiot basically trying to strip something there is no cause for any damage. [nut very tough to turn aproach with caution, it's probably already about as tight as it gets]
Look down on the nut, lefty loosey - more neck relief, righty tighty - less relief, to straight, into backbow.
Fret at first and last fret and observe the distance between the top of 9 and the bottom of the string to gauge relief.