Using a multimeter to check for problems in electric sockets
To check grounding and polarity a simple outlet tester like this would be a better tool for the DIY home owner. This type of tester will show if the outlets are grounded and can test GFCI breakers by pushing the button. With home wiring checking the resistance is not a very good test because there may be a low resistance with an unloaded circuit but under load the resistance can increase (ohm meters do not work on live circuits). you can also check the voltage on a circuit but if unloaded the same problem can arise with a circuit with no load you may see 120 volts but then a load the voltage can drop significantly. Making sure not to over load outlets (not adding power strips) and running circuits below 80% of there rated capacity is all that is needed in most homes.