Who do I contact and how?

Is this an invention of some sort?Are you in USA? If so, the U.S Patent Office may be an agency for you. Of course, hiring a patent attorney is an essential.

However, that being said, without some sort of clue or more specifics about what you're on to there's little most can do here to help.

{Edit: you posted this in Archaeology Forum. If this is some sort of an archaeological artifact, then try Smithsonian or National Geographic for starters. }

I can't think of anyone in the forum that is an archaeologist, however there might be someone that might steer you better than I.

If you are talking archeology I would probably start with the nearest large University. From there, somebody proficient in the appropriate field of study can review what it is you have and help get your find going in the right direction (which may be somewhere or may be nowhere, but they will have the appropriate contacts if it is something).

To get on Nat Geo's or the Smithsonian's radar you are going to need some sort of professional peer reviewed findings.

I agree with Tibble, going to a local University is the way to start. You need to find someone with expertise and some level of credential (i.e. a PhD and maybe some papers published on the subject).

You should also accept the possibility that maybe your discovery is not as impressive as you think. If you find someone with education and expertise, hopefully they will be able to tell you.

I would call the archaeology department of my local college.

What did you discover?

I believe I've found a previously unknown Nazca Line (symbol) using Google maps. I really think it's legit. It's human like figure with distinctive features, head, eyes, body, arms and legs.

Try a local college or university. What did you find? Are you sure you know what it is, or are you guessing?

Awesome!

I posted above your comment about it