As mentioned earlier, it's up to your preference... but then if you've never tried it you won't know if you like it right??
Anyways, a easy way to measure how high the action (or relief) is on your bass is to
1) fret at the first fret (i.e. F, Bflat, Dsharp, Gsharp) for the string you're testing
2) use your right thumb to fret at the 21th fret and...
3) use your index finger to tap on the 12th fret.
The space that is underneath the string above the 12th fret is how high your action is. Mine is just about the thickness of a credit card.
There are 2 ways to adjust the action on your bass
a) Adjust your truss rod
b) Adjust the height of your saddles
I think I've posted here before, but I'll do it again anyways. This is a great site to learn more about it -
http://www.garywillis.com/pages/bass/bassmanual/setupmanual.html
Just remember to check the intonation of your bass once you are done fiddling with it