My dog has two 'callus' like spots, one on each front leg, just smaller that a dime size, on the front part of the leg and up from the wrists about 2". He keeps liking them and I am not even sure if they have been there before I started noticing them. Is this something that I should be concerned about of do dogs have these spots?

The callous like spots are most like just that... callouses.

They are caused by too much pressure on an area of skin. There are a few ways to deal with it, the first being introducing moisture to the skin.
You can get a variety of dog moisturizers specifically for this purpose but many human ones do just as well. I find Vitamin E cream very good for softening the skin and relieving discomfort.
Another way to hwlp combat it is to provide softer sleeping areas. Laying on concrete, floorboards or tiles can make callouses worse so introducing carpet rugs, soft dog beds or hammock beds can also help.

You mention that the areas are on the front of the leg. I am guessing that you mean just above the carpal joint and not the elbow.
The carpal joint would be the joint on a front leg just above the dewclaw (the toe on the side that looks out of place)
If this is the actual location then what you may be seeing is what is known as a lick granuloma. Basically these are a sort of callous that the dog causes by continually licking at that spot, most dogs do it out of boredom.
They are pretty harmless, but they are unsightly and they don't usually improve if the dog keeps at them.
They can be treated with a topical solution, that you can have prescribed by your Vet.
Of course he is the only one who can tell you if that is in fact what they are.

Yes, sounds like a lick granuloma.

If so, these are the result of an obsessive disorder wherein the dog continuously licks, or wants to lick that particular spot. Any spot will do, as long as it's easy to get at with the mouth. It is often associated with a degree of boredom in the dog's life, and responds more to efforts to alleviate the boredom than prevention of the licking.

In extreme cases, surgery has been done, as a last ditch effort, to 'remove' the 'offending' lesion part of the skin on the leg, or foot, or whatever easy to reach spot the animal has selected. Bitter or unpleasant tasting topicals usually fail, as do attempts to cover the area to prevent contact by the mouth. In fact, that's just introduces a variation on the 'game', namely, 'get it off'. Injections to deaden the area usually fail as well, since this introduces a sensation of not being able to feel the chewing or licking.

Any 'success' in treating a particular spot often results in selection of a different one, like the other leg, unless the underlying cause is addressed.

Best idea is to give your vet a chance to correctly diagnose the problem and treat it accordingly.

Oh shoot, ignore my comments, I missed where it was on the front of the leg, agree with Paleo and Lady Sam.