What kind of stuff is he trying to find?  I like old homesteads and rail road camps myself.  If he spends any time out in the desert hunting/exploring/whatever, tell him to keep an eye out for purple glass and if he finds any, mark the spot for future detecting.  The book Ghost Towns of Arizona is a good resource for finding some old spots to detect.  

Parks and other places where large gatherings take place are good for finding clad change and jewellery.  Just make sure to tell him not to destroy turf or leave a bunch of holes.  Speaking of holes, it's good etiquette to always rebury your holes after digging something up.  

If he can get permission to detect a 60+ year old house, there is likely to be a silver coin lurking somewhere about.

I have the same detector.  I like that it is light weight but wish it had better discrimination for use in trashy sites.  That said, with a little use, one can get a pretty good idea if something is worth digging up or not.  Unfortunately, gold and pull tabs read about the same.

I have only been detecting for a couple years.  My coolest finds to date have been old cartridges.  I still haven't found any old coins (I have found clad in parks and schools).  My grandpa has been at it for about 50 years and has found all sorts of neat stuff, including tons of 100+ year old US coins and trade tokens.  He has also found a lot of old Mexican and Chinese coins at old rail road camps.  A few years back, he found a $5 US gold piece that I believe was from the 1880's.