On some multimeters, like the Simpson 260 series, the RED lead is actually NEGATIVE when on a resistance scale. As the owner of a multimeter it's up to you to verify whether this is true for your meter and either trust your memory or make some sort of a reminder on the meter itself. I have several Simpsons, AN/PSM-4s and other instruments with Dymo labels on the glass reading "RED LEAD NEG ON OHMS".
As for checking the bridge, you have two terminals with AC applied and two with the DC produced by the bridge. I generally open one corner of the bridge if it's possible; doesn't matter which one. Then I measure forward and backward across each of the diodes, using the Rx10 or Rx100 range and looking for any diode that doesn't show a good F/B ratio.
Then, don't forget to reconnect the corner you opened!