I agree with Don.   You want to make sure you forget the "standard" resolutions that used to be so common... 1024 x 728, 1280 x 1024, etc.   Pick the resolution that has the same aspect ratio as your screen.   Common is 1440 x 900.   HiRes screens are 1920 x 1200.    My Dell also has 1600 x 1200, but I've seen 1650 x something on some other Dells.

And, I also agree that you should move the task bar.   Don's is on the right.   Everyone at MapShots has settled on the left.   And I really, really, like the task bar on the side.  You get a working area that is more of the conventional monitor aspect you are used to, so it feels like you got extra space given to you.   And I think you can get much more on the task bar in less space.   I don't know how that is possible, but look at my QuickLaunch icons.   I can't imagine trying to have all of those with a taskbar on the bottom.

I run my second monitor on the left, so that puts the task bar right in the middle of the two sets of open applications I would be working with.  Puts it in easy reach from either monitor.