I have a standard procedure I use on all my new machines that works pretty good.
1) Of course, read the manual. Learn the machine in your mind before you turn it on.
2) Gather together a variety of targets...coins of different denominations, gold jewelry, Civil War relics if you have them, and trash targets as well...pull tabs, bottlecaps, a rusty nail or two.
3) Lay everything out on a blanket in some clean outdoor area, away from the house or any house trash, electrical lines, etc.
4) Start out in factory preset mode and scan all the items, to get a feel for how the machine acts. Practice pinpointing with it. See how it acts going from one good target to another, how it acts when you have a good target near trash...how the "recovery" or reset between targets is. See how many of the targets you've selected are discriminated out in the factory mode. Depending on the type of hunting you do, consider opening up the disc a bit. Switch between Smartfind and Digital modes a lot, like on every target for a while. Alll you have to do in order to do that is press the "Detect" touchpad. Get a feel for the Smartfind screen AND the numbers. I actually prefer to hunt mostly in Digital and mostly in "Iron Mask" at IM -16, where you hear EVERYTHING, nothing is discriminated, and you dig what sounds good or shows you the right numbers. I DON'T recommend this for a new user, though depending on your level of expertise, you may want to try it with your test targets, to see how that goes.
5) Take the machine out to an area you've hunted before, assuming this is not your first machine. See how it works in the real world. Get some hours behind it. Make note of your questions and post them on the Explorer Classroom forum.
6) Once you're comfortable with the machine, you can worry about "tweaking it up". If you feel you're a "little ahead of the curve", go for raising the sensitivity a little if you have some clean ground you're working in...maybe to 22 or so to start, more later.
That's about it to start with. I've done this with about 6 new machines and I feel it's a good way to start and get up and running as quickly as possible. Too many people run out there and turn the thing on and start hunting without considering much of the above. The machines usually end up on eBay or the Buy/Sell/Trade forum.
Here are some links you may find helpful:
http://mikesweather.metsite.com/detectin/html/explorer_xs___explorer_ii.html
http://www.frontiernet.net/~jvokes/simple.htm
http://groups.msn.com/MinelabExplorerXSusers/digitalchart1.msnw
http://www.bdomineau.com/index.html
http://usetheminelabexplorerlikeapro.blogspot.com/
