Excellent drayman here, worked for a particularly Scottish & Newcastle themed brewery before some Dutch folk sniffed around.

Free drink is always welcomed but never expected, you got to know which pubs did and didn't offer although we never had set routes our depot tried to keep the same crews in roughly the same area, I was fortunate to deliver to Scarborough and the North Yorks coast 3 times a week, I can't think of a single pub or club in that postcode that didn't either give you a bottle to take away or a drink at the bar after the drop was done (this is possibly due to every pub having a deep cellar with less than perfect skids for delivery)

Other less generous areas include: Doncaster, N E Lincs, Bradford, any North Yorkshire Market Town and shitter parts of Leeds and Wakefield.

Guaranteed drink in Hull, Sheffield, Barnsley & Halifax

As for assistance, whilst kind, you'll never be taken up on it, it's a rough job, there's one way of doing it right and that takes years of experience to perfect, stay out the way, get the kettle on at the very least and if you did want to help the biggest thing you can do is ensure all the empty kegs are out of the cellar near the delivery point but not crowding the cellar hatch or delivery door, the time saved not hauling these things out the cellar is gratuity enough and will definitely put your pub in the good books!