Querying when there are two authors?

Not sure if this is the best place to ask this.

I wrote a book (hooray!) with a co-author. We're going to be ready to query soon and have no idea how to handle the fact that there are two of us. Neither of us are published, so we don't really have anything to include in the bio section, but would that be the place to acknowledge that there are two of us? (and if so, any advice on what to say?) Or do we just sign it with two names and not include any additional information?

Thanks! I had tried to search to see if there was any advice already out there but I must have been using the wrong search terms.

It's good to know we should only list one of us as the contact. We had set up a joint email account, but in hindsight that might be a little too cutesy.