Paul Whitlock at Holman Moody is conducting annual maintenance this month. Although my car has crush sleeves installed on all four hubs, wheel bearings are a constant maintenance issue to check.
Different Dave here, but rears also require disassembly and greasing. I do mine about every 6-8000 miles. Rears require disconnecting drive axle at outer flange and removal of stub axle inside hub usually with a special tool Olthoff sells. Some have fabricated their own tool and some are able to do without the tool depending on spline tightness.
Lee, both front and back have the same issues. If you haven't had someone make crush sleeves for all four spindles, I'd check the bearings at least once per year.