As for neighborhoods that should be avoided, first any agent who would make a guess at that could be accused of several unethical violations so I won't go that route and second as an Elk Grove resident for over 40 years, Elk Grove is a desirable community at large and in the current market, investors lucky enough to acquire properties in Elk Grove are in a rare group right now , opportunities are what you have to look at based on condition and your desired role as a landlord. Investors looking for homes right now are in a large group looking at limited inventory.
My advise to our investor clients is to try for homes with stucco siding versus wood or lap siding....average homes like 3BD homes, 2 car garages, tile roofs or anything above a comp shingle. Pools can be a liability and increased maintenance but will help with resale.
Homepointe property management has a rental survey located under their owner services tab compiling a survey of what they have units rented for in each zip code etc, this can be helpful.
Be wary of top of the market rent desires, this can lower long term occupants if they can find something even a few hundred dollars cheaper.
Best of luck
Realty World eCurb REALTORS