Wheel Bearings

Hi all, I'm new to the forum, just got my first Bimmer, a '92 E36 325i with 139k miles. Don't know much about wheel bearings . . . how long do they typically last, and should get them checked considering my mileage? What are the telltale signs?

The signs are a slight humming noise . . I just replaced mine at 260,000 . . . and they where only $75.00 and other $100.00 to install

I have a 92 325i too