Discuss expectations with your potential guest about meals and/or kitchen privileges, bathroom usage, and sleeping arrangements. Do you have pets? Children in the house? Allergies they should be aware of? Do you work unusual hours? Is a certain amount of notice before arrival necessary? Your Warmshowers profile is a great place to share all of this information in advance. Keep things as straightforward as possible.
Shower facilities can be few and far between when camping regularly, probably the first thing your guest is going to want to do is get cleaned up. Give them a little space to do so before peppering them with questions about their trip (but ask those questions later!). Show them a secure place they can leave their bikes and gear, and an appropriate area to clean their bike if possible or needed.
If your budget doesn't allow you to feed your guest, let them know in advance so they can make other arrangements. Food is fuel for traveling cyclists, making their appetite likely to be measurably more than yours. Recommendations for nearby restaurants is a plus.
Treat your guest the way you’d expect to be treated if you were invited into their home. Keep agreements made about time and place, if your schedule changes for any reason, let your guest know.
Be a Resource
If you plan to host regularly, it's nice to have a stash of resources collected in advance so you don't have to repeat yourself every time. A map of your local area is invaluable for locating services cyclists might be interested in, everything from your favorite bike shop to grocery stores and restaurants. Offer directions for the best way out of town that just happens to pass a great bakery or unbelievable scenic view.
Trust Your Gut
If you feel uncomfortable about the situation for any reason, don’t agree to host. If something does not feel right in your first conversations, it likely isn’t a good fit for you, listen to that. Thank them for the inquiry and pass on the opportunity.
A Little Goes A Long Way
Even if it doesn't seem like a big deal, limit the amount of time any one guest stays with you. Remember what Benjamin Franklin said, “Guests, like fish, begin to smell after three days.” This goes for serial hosting as well.
If you are on or near a popular bike route, you may receive many requests for hosting, be aware when you are reaching your hosting threshold, no matter what that limit may be. If you’ve had a run of guests, it might be time to take a break before welcoming any more. It’s ok to say no.
If all of this sounds like a lot to consider or manage, or if a little spontaneity is not a good fit for your life right now, being a host may not be in your best interest for the time being. Be aware of your limits and needs and honor them for everyone's sake.