Hi Joe,
I have a probe for my FoxAlien machine, and I think it is an unreliable piece of junk. Brandon and I will disagree on what is more reliable, and you will make your own decision after trying both methods.
One thing I will say about a probe is that you have to specify what the thickness of the probe is - they are not all the same. Even following that, I found that my Z-position was not correct, but I find a piece of paper to be reliable and analog (I can see it), which I prefer. I will not insist that either method is better. It is what works better for you.
Anyway, as Brandon said above, except I will expand a bit on how I do things. I like to set my Z-zero directly to the piece, and typically close to the middle of the work that I am going to carve. If for example I was carving a circle, I would move my bit to the middle of said circle, and then lower my bit at the center of that circle. I use a small piece of newspaper, because that is a very thin piece of paper, and I have a plentiful supply. I lower my bit until it touches or is just about to touch the paper. Then I change my Z step size to 0.1mm, lower the bit, and move the paper. Lower it another step and so on, until the paper will not move or will tear if it does move. I set Z-zero there. I change my step back to 5mm, raise the bit, remove the paper, and I am ready to carve. I find this to be more reliable than the probe, because with the probe it never actually touches the surface and you click Carve expecting it to work properly and don’t really know for certain that zero is where you want it to be.
For two-stage carving, I do the same thing. Change the bit, HOME, and then move to a spot on the workpiece that has not been carved, put down your piece of paper and lower the bit in the same way.
Brandon or others in here may be able to help you better than I can if you do wish to use a probe. You have to set up your probe for thickness and there is a setting that needs to be correct in order for it to work properly.
Although I use Easel for design and creating my g-code, and I have tried several times to use it to do the carve, I do prefer to use UGS (Universal G-Code Sender) to do my carving. I really like being able to trace my work (which I can do in UGS, but not in Easel) before I hit start or carve, and it tells me more information and shows in real-time what is happening. Everyone has their own preference, and you will find yours.
Good luck with your cabinets! I am working on building two bathroom vanity cabinets right now. One I am doing old-school by hand, using pocket screws, dowels, glue, saws, handheld and table router, measuring and using my hands and brain. The other I am doing on the cnc (and designed in Easel) just to see how it works out. So far the cnc cabinet is taking significantly longer to do (like four times as long for a cabinet half the size), but when it is done I will have the files and should be able to reproduce it without having to use my old tired brain. 
I do want to ask you, because I scrolled through and I didn’t see where you may have identified your machine. What cnc are you using?