Specifically to South Lake Tahoe...
If you go down Pioneer Trail (the first light off of US 50 past the bug station into the main part of town), be aware there's a school on the right hand side of the road. In addition, police patrol this area (hit-n-miss heavily or not at all) and conduct their DUI checks (e.g. Monday was a DUI check). Don't obviously OC on this road until you reconnect to US50.
The Heavenly village (Starbucks, Raleys, Sports LTD, etc.) shopping area is okay. A lot of tourist, and when I've OC'd, never had a problem. Though a lady did shoot herself a year or two back, accidentally.
Never tried to OC in the Casino's right past Stateline (not really a gambler and only set foot into there ~1 / year).
Once you cross stateline into Stateline (name of the town), you're OC good-to-go. There are a few parks around (e.g. Nevada Beach right off of Kahle Dr.) which you can not OC *UNLESS* you have a NV CCW. This holds true for many of the state parks in NV (some weird wording of the law lets you OC if you have a CCW, but otherwise it has to be locked up and unloaded).
However, there is a ton of NF land. So you're free to shoot there (1500' with a handgun/rifle, 500' with a shotgun away from houses though) to your hearts content.
If you drive up US 50 to Carson City, you're clear. Nothing is really out there but there are some nice scenic views (e.g. Cave Rock). The schools are set far back enough from the highway such that you don't need to worry about them.
If you drive up 206 to Genoa/Minden (oldest settlement and a lot of bikers stop at the oldest bar w/ the bra's) then there is a elementary school if you continue north to Carson City. Just watch your speed as you go by it, and you'll not have any problems (never seen a sheriff in that area, but NHP does use that road). You will want to go slow right out of Genoa as there are a ton of deer.
Oh yeah, as you drive up 206 to Genoa, right past Wally Hot Springs Resort on the left, people pull over and shoot. Big flat area, easily 50 yards and lots of places to set up. This seems to be a locals favorite (men, women, children) for practice.
South of Carson you'll hit the first shopping area (BestBuy, Walmart, In-n-out burger, Trader Joes, Costco, etc.). All of them are OC friendly (I've even OC'd in the Costco) and will pay you little mind.