Go for it!
We've been running an AirBnB in St Marys for about 5 years now. AirBnB really treats its hosts very well, and we've also been treated very well when we traveled as guests.
We've been AirBnB "Superhosts" for three years running. With over 100 reviews, our rating is over 4.9 out of 5 stars. We take great pride in providing top-notch service. We have a lot of repeat customers - who tell us we've got the best AirBnB in the area, and they're always happy when our calendar is open for their return. We're often booked over 90% of each month.
Yes, we do pay taxes on the income. So the feds, state, and county each get a cut. We run it under a separate LLC with Schedule C reporting.
We have had a few minor incidents of damage, not malicious but just guest mistakes (soiled sheets, minor furnishing damage). We did not report them to AirBnB. But AirBnB does provide a large insurance coverage for hosts, provided you follow all the rules and policies.
Some recommendations:
You'll do a lot better if you provide a space that is fully devoted to your guests, rather than shared with your family. A separate entrance and living spaces means you don't have to interact with them constantly, other than to check them in and out. And you'll be able to host when you are not in town. Since it's an upstairs portion of your home, you might need to add a lockout door, and an outside stairway with 2nd level exterior door. But you'll get more guests (people want their own space) and better reviews.
Provide an electronic keypad lock. That way guests can check in without you being present. We program ours to our guest's cell phone last four digits, which makes it easy for them to remember. Since we reprogram it for each new guest, there are no issues with security against previous guests. You can buy locks that you can program remotely, but we're suspicious of depending too much on the internet to keep things running. A few in-person button presses isn't a big deal.
These days, provide good internet access, and to really make people happy, give them a Roku on which they can log in with their own Netflix or YouTube TV account.
Even though "BnB" stands for "bed and breakfast", you don't necessarily need to provide breakfast. Many of our guests don't care about the food at all. But be very clear in your description what you're offering.
However, providing food prep facilities increases your guest options. We have a small kitchenette with a microwave and fridge and small sink and dishwasher, but no stove. (We also offer a toaster oven and portable induction cooktop.) That opens it up to long-term guests, and we have had many people stay for several months (one guest stayed nearly 9 months). We really like that because we don't have to clean as often; they are responsible for daily maintenance. We only have a deep clean when they check out.
Get some NICE photos taken. AirBnB offers this as a service, if you don't have the equipment. Don't just take cell phone pics. It should look like those glossy hotel brochures; you're selling your space from the moment they click on your link. And for heaven's sake, stage it well.
Make sure the photos reflect reality. If it's in the photo, it better be there when they arrive.
Buy plenty of linens and towels. Get a LOT of sets, at least 2-1/2 if not 3 times what you will need for a maximum visitor rental. (For example, if you can host a max of six people, get 18 sets of towels, and three sets of linens.) You want to be able to flip the space over quickly without having to wait for laundry to run several loads, and you WILL end up with damaged linens and towels over time, so you want plenty of spares. Oh, and get high-quality stuff - it probably won't be mentioned in the reviews, but you WOULD get bad reviews for cheap stuff. All those little touches add up to happy guests and good reviews. (Pro tip: you can find low-price but good quality stuff at Ollies and other local bargain stores, for WAY cheaper than the main stores.)
Price it low to get started. Rapidly getting a stack of five-star reviews will take you a long way to building a successful brand. There's nothing in the reviews or ratings that will show your pricing at the time of the review. Then after a few months you can bump up your rates to the local average and make a bit more money. But keep rates low enough to keep the space filled - you make more money in the long run if you're constantly booked at a lower rate than occasionally booked at a high rate.
Think carefully about the balance between daily rates and cleaning fees (one time tacked on each rental). Many people are unhappy with low "teaser" rates but a high cleaning fee. You'll lose short-term customers that way.
You can and probably should be choosy on who you accept as a guest. If you're too choosy you'll hurt yourself in the rankings, but if you're letting someone onto your property and into your home, you want to be safe and secure. (For example, we rejected one guest who asked if it was okay if she used our room for a boudoir photo weekend with multiple clients. Uh, no. And we have rejected a few suspicious booking requests that sounded like they might be involved in human trafficking or other questionable things.)
You have to be willing to accept renters you might not choose to go to dinner with. We're unhappy about a lot of trends in our society, but we've hosted literally all kinds of people, some of whose lifestyles are offensive to us. Our welcome package makes our religious leanings quite clear - we're not ashamed of our own moral positions. But we treat them right, no matter whether we like their life choices. And they have all been friendly people and respected us in return. Hopefully in the process, we let them see that people labeled like us can be decent folks too.
I have a lot of things to say (lessons learned) about the booking system and website, but that's another day's conversation.
So go for it, and we welcome the competition!