What are the work and reloading benches?

[SurfDawg]

How do I use them and what do they do?

[Ladez]

They are crafting stations. Weapons, gadgets and other items are crafted at the workbench and ammunition is crafted at the reloading bench. There are also campfires, which lets you craft food items.

[psychotron666]

Try to use one, and you will see a list of recipes of things you can make. Just scroll down and check them out, they all require materials and some of them require skills to be a certain level as well.
You can also unlock more recipes with perks and from people in the game

[EolSunder]

Yep lots of fun crafting to do in the game. Now noted most things aren't worth crafting, but many are very awesome.

Workbench lets you make various items from mostly misc material. You can make weapons (bottlecap mines), helpful items (weapon repair kits) and a variety of other things.

Campfire or stove camp lets you make items from food materials. Not super useful in the regular game but very amazing if you play hardcore or hardcore logans loophole character.

Reloading bench lets you make basic ammunition from other ammunition. So if you like using 1 type of pistol and run low on the ammo, you can use similiar pistol ammo to craft more. If you take perks like hand loader, etc you can make bonus ammo for rifles, or laser ammo with that perk, or explosives with mad bomber perk, etc.