Upon a "mouseover", you can get a bit of information (this screenie is on herbs, but it works with ore as well). You can see the last time that YOU picked the node (not if someone ninja'd it from you), the distance, and what actually spawned at that point. The pic to the right shows what is in your "immediate" area, listing circles where the nodes have previously spawned (and in this pic, you can see an acual node respawn).

If you click on General, it will pull up this screen. To have the settings like I use, you need to have the "Display nodes on WorldMap" checked (highlighted in yellow in the near upper left of the window).

There are a few other options that you can use, however I prefer to keep the simplicity for only the things that I use, I am sure folks that use this will add in comments if there are other options that they enjoy (and a how-to) in case I missed something.
Now I am guessing that there are some folks that are thinking "It's not worth my time to gather (mine or herb), I make more at the AH". Well, if you enjoy sitting at the auction house all the time and don't get out in the real world, well, that's your perogative. As of late, I am enjoying getting back into the game, and after an hour in Twilight Higlands picking Jasmine and mining Elementium Ore and Pyrite, I hit 2200g (pending auction sales) in 60:02 minutes. Without going into further detail on that (I know, you guys probably miss that), even fighting a drood "bot" (i think at least), I still had no issues hitting the over 2K GPH. =)