advice on starting bones

 Marrow  bones/ RMBs.

The ones that look like this!

 
nom nom nom nom

But you'll want to scoop out some of the marrow because it's pretty rich and might upset Circa's tummy.

Marrow bones, rib bones, knuckle bones, chicken thighs/legs/quarters.

 Chicken wings. They are soft and pretty easy.

thanks for all the advice. I'll head out to get her one today. Is there a point where I should take the bone away--or can she just keep chewing on it?

 If you go with something edible (pork or chicken), get something small enough that you can let them eat the whole thing. You don't want to give them a huge chicken quarter first thing or you'll have a poopsplosion. They need to build up the flora and enzymes they need to digest raw meat and bone, gradually. It takes about a week or two, depending on how much variety your dog is already used to (different dog foods, wet and dry, "people food";).

I like pork ribs and neck bones because they have the fun of eating them entirely, which is also good for them, and they are cheap and readily available. Lamb's good too but it's hard to find and expensive (unless you raise them or know someone who does). Chicken quarters are SUPER cheap and are a key part of our regular diet here.

"just for fun" bones are called recreational bones and include bones that aren't very easy to break in pieces and swallow, like beef, bison, and venison. I love beef ribs - they aren't overloaded with marrow and the dogs can gnaw just enough of the ends to keep them interested for an hour or more - and come back for more later. I also get whole cow feet, which the dogs do backflips for, though the ewww factor might be too much for someone just starting out. I'm not a big one for those femurs for the smaller dogs. I do get big bones for the Maremmas from a couple of local grassfed beef operations - I feel the pasture raised calves yield bones that are less scary-brittle.

Once a dog is used to a rec bone, I let them clean off the whole thing then I fling them outside. The dogs will keep picking them up and working on them until I get tired of looking at them and collect them - or until I mow and throw them all out so they don't get chopped up in the mower.

All bones should be fed raw, of course. 

My dogs aren't big on chicken..only Jules will eat it, and even he looks at it oddly. So, we do a lot of ribs here. Beef mainly, as it seems easier to find for some reason. But I'll also do pork and lamb (the latter when there is a sale). There's also a meat market here that sells frozen meats, that will sell a huge frozen bag of ribs for $2. They're cut, so are ideal for my small kids (even Ginger can now take turns with bone time, which is great) and I can just give Aesop a double piece, which is perfect for him, as he's a delicate chewer. I usually give them frozen.