There are numerous figures now available for the home guard. I shall however only cover the scales 15mm to 28mm (25mm with knobs on).
In 15mm Peter Pig make a range of WW2 figures, including a home guard pack. Stronghold Miniatures produce a range of vehicle in this scale.
In 20mm Stronghold Miniatures produce a range of figures, They also do support weapons and vehicles. The figures are OK, but not fantastic. Figures Armour Artillery Figures Armour Artillery do a range, and it�s very good. They also do some civilians, the figures are based on dads army. The range includes an ARP warden. SHQ do a large early war range, but no home guard figures.
In 25/28mm Foundry do a very small, but very nice range. The range includes an ARP warden. They also fit in nicely with the Call of Cthulhu ranges. They are also 'inspired by dads army'. Black tree do some late war stuff, but the French resitance may be usefull as armed civilians, they also do some vehicles, but again they are late war.
Vehicles will be a problem, except in 20mm, in this scale you are spoilt for choice, military and civilian, even home guard wonders FrontLine are cheap and have a very good range, Home guard vehicles too. In 25/28mm Sloppy Jalopy do some 1/48th scale vehicles for the inter war period. Millitary vehicles for the early war are harder. Peter pig do some 15mm millitary vehicles as do Stronghold Miniatures, Stronghold do specificly home guard vehicles. But in 15mm civilian transport will be a problom.