Where
There are 10001 FBOs at Long beach, which is a horribly complex and smog-ridden airport, but if you're both ATPLs I'm sure you'll find your way out without trouble. The locals do everything by GPS these days, but may grudgingly leave a barely serviceable VOR in the plane.
I hired from one last year and they had the most appauling and dodgy fleet I've ever used - so I'd not recommend them, except that I've lost details of who they were. There was an outfit there hiring AMF aircraft, a slightly unusual type and a little more expensive but the looked much nicer and if I went back I'd probably give them a go.
Places
I enjoyed Mojave for it's sheer novely, have been into a lovely little gliding field called "Warner Springs" where given more time I might have stayed a day or two and done some gliding, enjoyed the friendly little municipal airfield called "Thermal" at Palm Springs, and Palm Springs itself - just because it is!
I've not yet managed Catalina, but everybody tells me that it's the destination in CA and apparently the Buffalo burgers are fantastic.
Also, a rather nice little "one-horse town" with a runway and some nice walks and eateries is "Yucca Valley" which is listed on the chart as an air park, but isn't.
Documents
The eastern US flight guide sold by Pooleys is the same one all the locals use, so no harm in buying one now for forward planning, it comes with a year's updates anyhow.
I shall leave others to comment on the PPL issues, I'm not up to speed enough, but hope that gives you a few steers.
G